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  • 251. Bergman, Gunnar
    et al.
    Nordell, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Sandberg, Karl W.
    IT for the citizens as a means of development of Lillpite village, Sweden1999In: Circumpolar change: building a future on experiences from the past : proceeding / [ed] Håkan Myrlund; Lars Carlsson, Luleå tekniska universitet, 1999, p. 289-303Conference paper (Other academic)
  • 252.
    Bergman, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Berkelund, Linn
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Nylander, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Olsson, Malin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Renström, Terese
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    HYDROGEOLOGISKA FÖRHÅLLANDEN I GÄVLEÅSEN: Analys av stabila syreisotoper och kemiska parametrar samt beräkning av flöden i Gävleåsen2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta projekt behandlar hur vatten rör sig i Gävleåsen, det vill säga åsens hydrogeologiska förhållanden. Gävle kommun tar sitt dricksvatten från Gävleåsens grundvattenmagasin. För att öka grundvattenbildningen i åsen används konstgjord infiltration av åvatten och grundvatten genom infiltrationsbassänger, infiltrationsbrunnar och en sprinkleranläggning. Projektet initierades med bakgrund att grundvattennivåerna i Gävle kommuns grundvattentäkt sjunker på grund av vattenuttaget. Syftet med projektet var att bestämma om variationer i halt löst syre, organiskt material, an- och katjoner samt stabila syre- och väteisotoper kunde användas för att förklara de hydrogeologiska förhållandena i Gävleåsen. Även storleken på flödet uppströms och nedströms om infiltrationsanläggningen samt blandningsförhållandet nedströms skulle fastställas.

    Tre modeller över hur flödet varierade i åsen utformades på grund av den stora osäkerhet som fanns vid uppskattning av åsens mättade hydrauliska konduktivitet som användes vid flödesberäkningarna. I den första modellen antogs att flödesmassbalansen i åsen stämde, det vill säga att flödet nedströms var en summa av flödet uppströms om och flödet från infiltrationsanläggningen. Den andra modellen byggde på att det skedde ett okänt nettoutflöde från åsen mellan flödet uppströms och flödet nedströms om infiltrationsanläggningen. Att vatten istället skulle ha tillkommit till akviferen från exempelvis Gavleån eller genom inträngning av äldre grundvatten undersöktes med den tredje modellen. Uppställning av en isotopmassbalans för de olika modellerna tydde på att alla modeller kunde vara en möjlig bild av hur flödena i Gävleåsens akvifer förhöll sig till varandra och infiltrationsflödet genom infiltrationsanläggningen.

    Vid beräkning av blandningsförhållandet mellan grund- och åvatten nedströms om infiltrationsanläggningen visade både syreisotopsberäkningar och beräkningar med kloridjoner att cirka 25 procent åvatten tillkommit i akviferen. De kemiska parametrarna löst syre och organiskt material visade sig inte vara lämpliga som spårämnen för att bestämma källor till ett flöde. Dock kan dessa parametrar användas för att bedöma om det skett en förändring i vattenkvaliteten.

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  • 253.
    Berrezel, Y. A.
    et al.
    Department of Hydraulics, University of Tlemcen, Algeria.
    Abdelbaki, C.
    Department of Hydraulics, University of Tlemcen, Algeria.
    Rouissat, B.
    Department of Hydraulics, University of Tlemcen, Algeria.
    Boumaaza, T.
    Oran Water and Sanitation Company, Algeria.
    Mourad, Khaldoon
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Decision support system for the management of water distribution networks a case study of Tourville, Algeria2023In: Larhyss Journal, ISSN 1112-3680, Vol. 2023, no 54, p. 7-24Article in journal (Refereed)
    Abstract [en]

    The analysis of the current situation of water distribution networks (WDNs) is based on many alternatives that are technically feasible and implemented by decision makers. Taking the WDN of Tourville city as a case study, this paper combines a set of decision support systems (DSSs), including geographic information systems (GISs), multicriteria analysis and hydraulic simulation models, to establish a multicriteria decision-making aid method for the renovation and rehabilitation of water distribution networks. This combination creates an expert management system based on multicriteria decision making that strengthens the optimization of the management of water distribution networks in terms of renovation and rehabilitation. After dividing the water distribution network into three emergency levels, it was concluded that 26% of the network is in urgent need of rehabilitation.

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  • 254.
    Bertino, Andrea
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Water, Sewage and Waste technology.
    Study on one-stage Partial Nitritation-Anammox process in Moving Bed Biofilm Reactors: a sustainable nitrogen removal.2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the last decade, several novel and cost-effective biological nitrogen removal technologies have been developed. The discovery of anaerobic ammonium oxidation (Anammox), about 15 years ago, has resulted in new opportunities for research and development of sustainable nitrogen removal systems. Compared to conventional nitrification/denitrification, Anammox eliminates necessity of external organic carbon source, has a smaller production of excess sludge, reduces energy demand for aeration (up to 60-90%) and CO2 emissions (up to 90%). Systems based on Anammox can be of great help to comply with stricter wastewater discharge regulations and reduce environmental problems caused by nutrients discharges (e.g. eutrophication).

    This thesis investigates the partial nitritation/Anammox in one stage system under oxygen limited condi-tions (also called CANON or Deammonification) and with the Moving Bed Biofilm Reactor (MBBR™) technology. Anammox process coupled with partial nitritation can be particularly suitable to treat ammo-nium-rich wastewater with low content of biodegradable organic matter, such as the reject water from dewatering of digested sludge, which is usually recirculated back to the main stream of wastewater treat-ment plants, accounting for the 15-20% of the total nitrogen load.

    Partial nitritation/Anammox process was successfully tested on a pilot plant scale for four months at 25°C, in a 200 L Continuous Stirred Tank Reactor (CSTR), filled with 40% of Kaldnes media (model K1). At an Ammonium Surface Load (ASL) of 3.45 gN m-2d-1, the removal rate was about 2.85 gN m-2d-1. Removal efficiencies of 95%, 85% and 83% were respectively achieved for NH4+-N, inorganic nitrogen, and Total Nitrogen (TN). Bacteria activity was followed by batch tests such as Specific Anammox Activity (SAA), Oxygen Uptake Rate (OUR) and Nitrate Uptake Rate (NUR), which revealed an increase in activi-ty for Nitrosomonas and Anammox bacteria within the biofilm. Dissolved oxygen concentration in the bulk liquid was a crucial parameter, whereas pH and conductivity turned out to be two useful monitoring tools.

    Two laboratory-scale reactors were previously run for two months each, in order to evaluate the one-stage partial nitritation/Anammox process with a lower ASL. One reactor was fed with diluted reject water, whereas the other one treated the effluent from UASB (Up-flow Anaerobic Sludge Blanket) reactor after sand filtration. Fairly good efficiency (>75%) were reached but, however, in the last case the low ammo-nium nitrogen load could represent a problem for a stable full-scale installation and long-term growth of Anammox bacteria.

    Some suggestions for full-scale implementation and further research are proposed in the last chapter of this master thesis.

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  • 255.
    Beryani, Ali
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Organic micropollutants in highway stormwater and the role of a gross pollutant trap-biofilter stormwater treatment train2023Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The studies which this thesis is based on assessed the stormwater quality in a highway catchment located in Sundsvall, Sweden, and examined the performance of a gross pollutant trap (GPT)-biofilter stormwater treatment train (TT) downstream of the catchment, in terms of removal efficiency, intra-event variability, and environmental risk reduction of organic micropollutants (OMPs) for the receiving water body. Assessing the occurrence and event mean concentrations (EMCs) of all OMPs in the catchment revealed that bisphenol A (BPA), octylphenol (OP), nonylphenol (NP), five carcinogenic and four non-carcinogenic polycyclic aromatic hydrocarbons (PAHs), and C16-C40 fractions of petroleum hydrocarbons (PHCs) all potentially pose an environmental risk to freshwater (EMCs >PNEC: predicted non-effect concentration), while alkylphenolethoxylates, six low- molecular weight PAHs, and lighter fractions of PHCs (C10-C16) do not occur at problematic levels.

    In order to assess the impact of the downstream TT in mitigating the risks of the studied OMPs, the performance of the TT compartments (a GPT followed by three filter cells) was analyzed and then compared with each other to identify the importance of each design feature (i.e. pre-treatment GPT, sand-based filter media, vegetation, and chalk amendment). Overall, the TT removed most OMPs from highway runoff effectively. The GTP did not contribute to this treatment, thus, the filter sections were responsible for most of the OMP removal. The results showed that, although the non-vegetated sandfilter (SF) could moderately (<50% removal for phenolic substances) to substantially (50–80% removal for PAHs and PHCs) treat the OMPs, the vegetated biofilters (BF and BFC) considerably improved the removal performance, especially for BPA, OP, and suspended solids (TSS). This observation was explained by additional filtration processes provided by the vegetation topsoil layer, which not only enhanced the particulate/particle-bound OMP physical retention but also physiochemical adsorption of colloidal and soluble substances/fractions (such as BPA and OP).

    Further analysis of intra-event concentration (IEC) variations of OMPs and TSS showed that the IECs in the highway stormwater and GPT outflow varied considerably without any particular patterns over the course of the events, but first flush rarely occurred. The IEC variations were attenuated by the SF and BFC cells so that more even pollutant load discharge with no first flush was observed during the filter cells’ outflow events. Yet, the IECs for the SF cell revealed that the IECs often peak at the beginning of the effluent events (within the first 100 m3 out of maximum record of ⁓600 m3) and then decrease and become stabilized towards the end of the event. The early-phase concentration peaks exceeded the PNECs for TSS, five PAHs, BPA, and OP, a fact that was not shown by the EMC-based analysis, thus highlighted the advantage of the IEC analysis.

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  • 256.
    Beryani, Ali
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Flanagan, Kelsey
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Datasets of a stormwater treatment train facility consisting of a gross pollutant trap and biofilters/sand filter in Sundsvall, Sweden2023Data set
    Abstract [en]

    The data were collected from a stormwater treatment train facility in Sundsvall, Sweden. The facility consists of a gross pollutant trap (GPT) followed by three parallel biofilter cells: a vegetated, chalk-amended biofilter (BFC or F1), a non-vegetated sand filter (SF or F2), and a vegetated biofilter (BF or F3).One of the objectives of our research project was to assess and monitor stormwater quality received from a major road catchment (incl. E4 highway bridge in Sundsvall) and also evaluate the performance of the various sections of the treatment train in removing organic micropollutants from the stormwater.

    The file named "StormwaterRunoffQualityData_SND.csv" contains event mean concentration (EMC) data on stormwater samples collected from 8 rain events (coded by A to H) in one year between September 2020 and September 2021. The samples have been analyzed for organic micropollutants and global water quality parameters (42 parameters in total). EMCs have been mathematically generated by a Monte-Carlo simulation from measured concentrations in sub-samples collected during each event. The data elaborate on the generated distribution for each EMC with Q2.5, Q50, and Q97.5 percentiles and standard deviation from the mean. Besides, the number of detected and non-detected (censored) data of sub-samples are mentioned. The list of all pollutants and their abbreviations are included in the documentation file named "StormwaterRunoffQualityData_SND.docx". Stormwater flow data are also presented in the file "VolumeData_Stormwater_SND.csv".

    The file named "TreatmentTrainQualityData_SND.csv" presents event mean concentration (EMC) data not only for the stormwater runoff quality but also for the treated stormwater in the GPT-biofilter/sand filter treatment train downstream of the catchment. In addition to the untreated stormwater runoff as the system's inflow (SW), EMCs have been presented for 4 more sampling points: GPT outflow (GPT), vegetated, chalk-amended biofilter outflow (BFC), non-vegetated sand filter (SF), and vegetated biofilter outflow (BF). For this part of the research, a total of 11 rain events (coded by A to K) were covered from Sep. 2020 until Sep. 2021. The samples have been analyzed for organic micropollutants and other conventional water quality parameters (42 parameters in total). EMCs have been mathematically generated by a Monte-Carlo simulation from measured concentrations in sub-samples collected during each event. The data present a distribution for each EMC with Q2.5, Q50, and Q97.5 percentiles and standard deviation from the mean. The number of detected and non-detected (censored) data of sub-samples is also mentioned. The list of all pollutants and their abbreviations are included in the documentation file named "TreatmentTrainQualityData_SND.docx". Flow data are also presented in the file "VolumeData_Treatment train_SND.csv".

  • 257.
    Beryani, Ali
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Flanagan, Kelsey
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Occurrence and concentrations of organic micropollutants (OMPs) in highway stormwater: a comparative field study in Sweden2023In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 30, no 31, p. 77299-77317Article in journal (Refereed)
    Abstract [en]

    This study details the occurrence and concentrations of organic micropollutants (OMPs) in stormwater collected from a highway bridge catchment in Sweden. The prioritized OMPs were bisphenol-A (BPA), eight alkylphenols, sixteen polycyclic aromatic hydrocarbons (PAHs), and four fractions of petroleum hydrocarbons (PHCs), along with other global parameters, namely, total organic carbon (TOC), total suspended solids (TSS), turbidity, and conductivity (EC). A Monte Carlo (MC) simulation was applied to estimate the event mean concentrations (EMC) of OMPs based on intra-event subsamples during eight rain events, and analyze the associated uncertainties. Assessing the occurrence of all OMPs in the catchment and comparing the EMC values with corresponding environmental quality standards (EQSs) revealed that BPA, octylphenol (OP), nonylphenol (NP), five carcinogenic and four non-carcinogenic PAHs, and C16-C40 fractions of PHCs can be problematic for freshwater. On the other hand, alkylphenol ethoxylates (OPnEO and NPnEO), six low molecule weight PAHs, and lighter fractions of PHCs (C10-C16) do not occur at levels that are expected to pose an environmental risk. Our data analysis revealed that turbidity has a strong correlation with PAHs, PHCs, and TSS; and TOC and EC highly associated with BPA concentrations. Furthermore, the EMC error analysis showed that high uncertainty in OMP data can influence the final interpretation of EMC values. As such, some of the challenges that were experienced in the presented research yielded suggestions for future monitoring programs to obtain more reliable data acquisition and analysis.

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  • 258.
    Beryani, Ali
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Flanagan, Kelsey
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Performance of a gross pollutant trap-biofilter and sand filter treatment train for the removal of organic micropollutants from highway stormwater (Field study)2023In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 900, article id 165734Article in journal (Refereed)
    Abstract [en]

    This field study assessed the occurrence, event mean concentrations (EMCs), and removal of selected organic micro-pollutants (OMPs), namely, polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), nonylphenol (NP), 4-t-octylphenol (OP), and bisphenol A (BPA), in a gross pollutant trap (GPT)-biofilter/sand filter stormwater treatment train in Sundsvall, Sweden. The effects of design features of each treatment unit, including pre-sedimentation (GPT), sand filter medium, vegetation, and chalk amendment, were investigated by comparing the units' removal performances. Overall, the treatment train removed most OMPs from highway runoff effectively. The results showed that although the sand filter provided moderate (<50 % for phenolic substances) to high (50–80 % for PAHs and PHCs) removal of OMPs, adding a vegetated soil layer on top of the sand filter considerably improved the removal performance (by at least 30 %), especially for BPA, OP, and suspended solids. Moreover, GTP did not contribute to the treatment significantly. Uncertainties in the removal efficiencies of PAHs and PHCs by the filter cells increased substantially when the ratio of the influent concentration to the limit of quantification decreased. Thus, accounting for such uncertainties due to the low OMP concentrations should be considered when evaluating the removal performance of biofilters.

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  • 259.
    Beryani, Ali
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Goldstein, Alisha
    Dept. of Biological and Agriculture Engineering, North Carolina State Univ., Campus Box 7625, Raleigh, NC, 27695, USA.
    Al-Rubaei, Ahmed
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water. Dept. of Building and Construction Engineering, Univ. of Technology, 19006, Baghdad, Iraq.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hunt III, William F.
    Dept. of Biological and Agriculture Engineering, North Carolina State Univ., Campus Box 7625, Raleigh, NC, 27695, USA.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Survey of the Operational Status of Twenty-six Urban Stormwater Biofilter Facilities in Sweden2021In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 297, article id 113375Article in journal (Refereed)
    Abstract [en]

    This study evaluates the operational status of twenty-six biofilter facilities across nine cities in Sweden, with respect to their functional design criteria, engineered design features (filter media composition, hydraulic conductivity, and drawdown time), and includes a visual inspection of the biofilter components (pre-treatment, in/outlet structures, filter media, and vegetation). These indicators were used to examine the performance level of each biofilter in achieving their design objectives set by the operators. Furthermore, it was investigated whether the biofilter facilities had been properly maintained to meet the objectives. Results indicate that the soil media used was consistent with respect to percentage sand, fines, and organic matter and comparable to design recommendations used by municipalities in other countries. The field-tested hydraulic conductivity for the biofilters ranged from 30 to 962 mm/h. This range of values, along with noticeable sediment accumulation within the biofilter indicate that not all the sites were operating optimally. Pre-treatment stages in poor condition with high volumes of sediment and litter accumulation were the primary causes for, and indicators of, low hydraulic conductivity rates. The ponding volume calculations revealed that at least 40 % of facilities did not have enough capacity to retain every-day and/or design rainfall due to design and/or construction flaws. These analyses raise concerns that, for a considerable number of the biofilters surveyed, water retention and flood protection identified by operators as prioritised objectives are not being met. This raises significant concerns about the functionality of biofilter in practice. Finally, some suggestions are given for tackling the design and maintenance problems discovered.

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  • 260.
    Beryani, Ali
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    The intra-event dynamics of the removal of organic micro-pollutants (OMP) in stormwater treatment trains: gross pollutant trap and biofilter2021Conference paper (Refereed)
  • 261.
    Betsholtz, Alexander
    et al.
    Lunds universitet.
    Karlsson, Stina
    Lunds universitet & Sweden Water Research AB.
    Svahn, Ola
    Kristianstad University, Plattformen för molekylär analys. Kristianstad University, Faculty of Natural Sciences, Research environment MoLab. Kristianstad University, Faculty of Natural Sciences, Avdelningen för miljö- och biovetenskap.
    Davidsson, Åsa
    Lunds universitet.
    Cimbritz, Michael
    Lunds universitet.
    Falås, Per
    Lunds universitet.
    Tracking 14C-labeled organic micropollutants to differentiate between adsorption and degradation in GAC and biofilm processes2021In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 55, no 16, p. 11318-11327Article in journal (Refereed)
    Abstract [en]

    Granular activated carbon (GAC) filters can be used to reduce emissions of organic micropollutants via municipal wastewater, but it is still uncertain to which extent biological degradation contributes to their removal in GAC filters. 14C-labeled organic micropollutants were therefore used to distinguish degradation from adsorption in a GAC-filter media with associated biofilm. The rates and extents of biological degradation and adsorption were investigated and compared with other biofilm systems, including a moving bed biofilm reactor (MBBR) and a sand filter, by monitoring 14C activities in the liquid and gas phases. The microbial cleavage of ibuprofen, naproxen, diclofenac, and mecoprop was confirmed for all biofilms, based on the formation of 14CO2, whereas the degradation of 14C-labeled moieties of sulfamethoxazole and carbamazepine was undetected. Higher degradation rates for diclofenac were observed for the GAC-filter media than for the other biofilms. Degradation of previously adsorbed diclofenac onto GAC could be confirmed by the anaerobic adsorption and subsequent aerobic degradation by the GAC-bound biofilm. This study demonstrates the potential use of 14C-labeled micropollutants to study interactions and determine the relative contributions of adsorption and degradation in GAC-based treatment systems.

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  • 262.
    Bhat, Shakeel Ahmad
    et al.
    College of Agricultural Engineering and Technology, Sher E Kashmir University of Agricultural Sciences and Technology-Kashmir, Srinagar 190025, India.
    Kuriqi, Alban
    CERIS, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal; Civil Engineering Department, University for Business and Technology, 10000 Pristina, Kosovo.
    Din Dar, Mehraj U.
    Department of Agriculture, Mata Gujri College, Fatehgarh Sahib 140406, India; Department of Soil and Water Engineering, Punjab Agricultural University, Ludhiana 141004, India.
    Bhat, Owais
    College of Agricultural Engineering and Technology, Sher E Kashmir University of Agricultural Sciences and Technology-Kashmir, Srinagar 190025, India.
    Sammen, Saad Sh.
    Department of Civil Engineering, College of Engineering, Diyala University, Baqubah 32001, Iraq.
    Towfiqul Islam, Abu Reza Md.
    Department of Disaster Management, Begum Rokeya University, Rangpur 5400, Bangladesh.
    Elbeltagi, Ahmed
    Agricultural Engineering Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.
    Shah, Owais
    College of Agricultural Engineering and Technology, Sher E Kashmir University of Agricultural Sciences and Technology-Kashmir, Srinagar 190025, India.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Ali, Rawshan
    Department of Petroleum, Koya Technical Institute, Erbil Polytechnic University, Erbil 44001, Iraq.
    Heddam, Salim
    Agronomy Department, Faculty of Science, Hydraulics Division University, 20 Août 1955, Route El Hadaik, BP 26, Skikda 21024, Algeria.
    Application of Biochar for Improving Physical, Chemical, and Hydrological Soil Properties: A Systematic Review2022In: Sustainability, E-ISSN 2071-1050, Vol. 14, no 17, article id 11104Article, review/survey (Refereed)
    Abstract [en]

    Biochar is a carbon-based substance made by the pyrolysis of organic waste. The amount of biochar produced is determined by the type of feedstock and pyrolysis conditions. Biochar is frequently added to the soil for various reasons, including carbon sequestration, greenhouse gas mitigation, improved crop production by boosting soil fertility, removing harmful contaminants, and drought mitigation. Biochar may also be used for waste management and wastewater treatment. Biochar’s various advantages make it a potentially appealing instrument material for current science and technology. Although biochar’s impacts on soil chemical qualities and fertility have been extensively researched, little is known about its impact on enhancing soil physical qualities. This review is intended to describe biochar’s influence on some crucial soil physical and hydrological properties, including bulk density of soil, water holding capacity, soil porosity, soil hydraulic conductivity, soil water retention, water repellence–available plant water, water infiltration, soil temperature, soil color, and surface albedo. Therefore, we propose that the application of biochar in soils has considerable advantages, and this is especially true for arable soils with low fertility.

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  • 263.
    Bhattacharya, Prosun
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Geochemistry and Ecotechnology. KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Water and Environmental Engineering.
    Mukherjee, A. B.
    Management of arsenic contaminated groundwater in the Bengal Delta Plain2017In: Conflict Management of Water Resources, Informa UK Limited , 2017, p. 308-348Chapter in book (Other academic)
    Abstract [en]

    In the first half of the 13th century, St. Francis of Assisi (1182-1226) predicted the acute importance of water, which he defined as pretiosa (Cascetta, 1995). Unfortunately, the world has forgotten this caveat and in recent years, the importance of water resources is finally receiving greater attention in our daily lives. This is the result of rising demands, declining availability, as well as treatment costs incurred as the result of pollution from industrial and natural sources.

  • 264. Bhowmick, S.
    et al.
    Nath, B.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Biswas, Ashis
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Majumder, S.
    Mondal, P.
    Chakraborty, S.
    Nriagu, J.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Iglesias, M.
    Roman-Ross, G.
    Guha Mazumder, D.
    Bundschuh, J.
    Chatterjee, D.
    Arsenic mobilization in the aquifers of three physiographic settings of West Bengal, India: Understanding geogenic and anthropogenic influences2013In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 262, p. 915-923Article in journal (Refereed)
    Abstract [en]

    A comparative hydrogeochemical study was carried out in West Bengal, India covering three physiographic regions, Debagram and Chakdaha located in the Bhagirathi-Hooghly alluvial plain and Baruipur in the delta front, to demonstrate the control of geogenic and anthropogenic influences on groundwater arsenic (As) mobilization. Groundwater samples (n=90) from tube wells were analyzed for different physico-chemical parameters. The low redox potential (Eh=-185 to -86mV) and dominant As(III) and Fe(II) concentrations are indicative of anoxic nature of the aquifer. The shallow (&lt;100m) and deeper (&gt;100m) aquifers of Bhagirathi-Hooghly alluvial plains as well as shallow aquifers of delta front are characterized by Ca2+HCO3 - type water, whereas Na+ and Cl- enrichment is found in the deeper aquifer of delta front. The equilibrium of groundwater with respect to carbonate minerals and their precipitation/dissolution seems to be controlling the overall groundwater chemistry. The low SO4 2- and high DOC, PO4 3- and HCO3 - concentrations in groundwater signify ongoing microbial mediated redox processes favoring As mobilization in the aquifer. The As release is influenced by both geogenic (i.e. geomorphology) and anthropogenic (i.e. unsewered sanitation) processes. Multiple geochemical processes, e.g., Fe-oxyhydroxides reduction and carbonate dissolution, are responsible for high As occurrence in groundwaters.

  • 265. Bhowmick, Subhamoy
    et al.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Kundu, Amit Kumar
    Saha, Debasree
    Iglesias, Monica
    Nriagu, Jerome
    Mazumder, Debendra Nath Guha
    Roman-Ross, Gabriela
    Chatterjee, Debashis
    Is Saliva a Potential Biomarker of Arsenic Exposure?: A Case-Control Study in West Bengal, India2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 7, p. 3326-3332Article in journal (Refereed)
    Abstract [en]

    Saliva is a biological fluid that has not been used extensively as a biomonitoring tool in epidemiological studies. This study presents the arsenic (As) concentrations in saliva and urine samples collected from populations of West Bengal, India who had been previously exposed to high As levels in their drinking water. We found a significant (p < 0.05) association between the Log transformed Daily Ingestion of As (mu g day(-1)) and the As concentration in saliva (r = 0.68). Additionally, As concentration of saliva and urine also had a significant positive correlation (r = 0.60, p < 0.05). Male participants, smokers, and cases of skin lesion were independently and significantly associated with an increase in salivary As. Thus our findings show that saliva is a useful biomarker of As exposure in the study population. The study also advocates that measurement of the forms of As in saliva may additionally provide insight into the internal dose and any individual differences in susceptibility to As exposure.

  • 266.
    Billstein, Mats
    Luleå University of Technology.
    Development of a numerical model of flow through embankment dams1998Licentiate thesis, comprehensive summary (Other academic)
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  • 267.
    Billstein, Mats
    Luleå University of Technology.
    Influence of fractures and air bubbles on the pressure distribution embankment dams2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In some large embankment dams unexpected pore pressure distributions within the core have been observed. As an example, the piezometer pressures in WAC Bennett Dam, Canada, which rose for about four years after the reservoir was filled, were steady for two years and subsequently declined. One peak pressure head was as much as 60 m higher than the expected steady state pressure head of 40 m. However, the pressure head had dropped 55 m from the peak value 25 years later. Four hypotheses have already been proposed to explain the anomalous pore pressures within embankment dams. The objective of this study is to examine two of them, inhomogenities (e.g. fractures) in the core and trapped air bubbles, which can both be examined from a fluid mechanical point of view. The other two mechanisms, settlements and bleeding of fine material, must also be examined from a geotechnical aspect. This examination, based on results from two numerical models, is mainly theoretical. Results from numerical simulations of simplified homogeneous and inhomogeneous embankment dams are compared with analytical solutions and basic experiments. Results from numerical simulations, including the influence of air bubbles, are evaluated using a plug flow analysis and field measurements. A Hele-Shaw cell and a bed of packed glass beads, both a homogeneous and an inhomogeneous experimental set up, were used in the examination of how inhomogenities influence the pressure distribution. In the inhomogeneous case, a horizontal fracture extended from the upstream boundary to a point within the embankment. The fracture was shown to have a significant influence on the pressure distribution, discharge, seepage level, and free surface profile. The numerical model is based on a direct solution of the conservation equations (mass and momentum). In the numerical simulations, the flow resistance is determined from a laminar velocity profile in a slot with smooth walls (Hele-Shaw cell) and from the Forchheimer equation (bed of packed glass beads). The problem is considered to be two-dimensional. Since air bubbles are always initially present in the voids, that air is compressible, and that the amount of air that can go into solution increases with pressure, a mechanism that generates hydraulic blockage in the downstream part of the core can be anticipated. The blockage decreases the hydraulic conductivity in the flow direction resulting in a pressure increase. The numerical model for this case is based on a direct solution of the conservation equations (mass and momentum) and Darcy's, Boyle's, and Henry's law. It is a two-phase problem treated as one-dimensional. The main result of the study is the development of numerical models to simulate how inhomogenities and trapped air bubbles influence the pressure distribution. These models have a solid foundation, i.e. are based on conservation principles, physical laws, and the best available empirical relationships. The models have been validated through comparisons with analytical solutions, basic experiments, and field measurements and thus provide a good starting point in the development of tools that can be used in dam engineering.

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  • 268.
    Billstein, Mats
    et al.
    Luleå University of Technology.
    Svensson, Urban
    Computer-Aided Fluid Engineering AB.
    A numerical evaluation of air bubbles as a potential explanation to the higher than expected pore pressures in the core of WAC Bennett Dam2002In: Journal of Hydraulic Research, ISSN 0022-1686, E-ISSN 1814-2079, Vol. 40, no 5, p. 623-630Article in journal (Refereed)
    Abstract [en]

    The objective of this study is to numerically evaluate if the Air Hypothesis is a potential explanation of the unusual pressure behaviour of the core at WAC Bennett Dam. Up to now, the pore pressures have exceeded the expected normal steady state distribution for about 25 years. The Air Hypothesis describes the influence of air bubbles on the pressure distribution in the core. An increased water pressure will compress the air bubbles and increases the amount of air that can go into solution at the upstream side of the core. At the downstream side, the situation is reversed, i.e. the air volume will increase and cause a hydraulic blockage. A one-dimensional numerical model, that is based on relevant conservation laws, physical laws (Darcy's, Boyle's, and Henry's laws) and the relationships between the relative hydraulic conductivity and water saturation level, is able to predict the pressure evolution in both a qualitative and quantitative way. The model is applied to both a hypothetical core and the core of WAC Bennett Dam. Results from a plug flow analysis on the dissolution of the air in the hypothetical core are in fair agreement with the numerical results. Comparisons with pressure measurements from WAC Bennett Dam show that the Air Hypothesis is a potential explanation to the unusual pressure distribution in the core

  • 269. Bishop, K
    et al.
    Rapp, L
    Köhler, S
    Korsman, Tom
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Testing the steady-state water chemistry model predictions of pre-industrial lake pH with paleolimnological data from northern Sweden.2008In: Sci Total Environ, ISSN 0048-9697, Vol. 407, no 1, p. 723-9Article in journal (Refereed)
    Abstract [en]

    Criteria are needed for distinguishing naturally acid water from that acidified by air pollution, especially in the organic-rich waters of northern Sweden. The Steady-State Water Chemistry Model (SSWC) was augmented to include organic acidity so that it could predict pre-industrial pH in organic-rich waters. The resulting model predictions of preindustrial ANC and pH were then tested against diatom predictions of pre-industrial pH and alkalinity in 58 lakes from N. Sweden (after alkalinity was converted to ANC using the CBALK method). The SSWC Model's predictions of pre-industrial lake pH in N. Sweden did not correspond well with the diatom predictions, even when accounting for the uncertainty in the diatom model. This was due to the SSWC's sensitivity to short-term fluctuations in contemporary water chemistry. Thus the SSWC Model is not suitable for judging the acidification of individual lakes in areas such as northern Sweden where the degree of chronic acidification is small, or without a good average value of contemporary water chemistry. These results should be considered when assessing the accuracy of critical loads calculated using SSWC.

  • 270.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Majumder, Santanu
    Neidhardt, Harald
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Bhowmick, Subhamoy
    Mukherjee-Goswami, Aishwarya
    Kundu, Amit
    Saha, Debasree
    Berner, Zsolt
    Chatterjee, Debashis
    Groundwater chemistry and redox processes: Depth dependent arsenic release mechanism2011In: APPLIED GEOCHEMISTRY, 2011, Vol. 26, no 4, p. 516-525Conference paper (Refereed)
    Abstract [en]

    Patchy occurrences of elevated As are often encountered in groundwater from the shallow aquifers (<50 m) of the Bengal Delta Plain (BDP). A clear understanding of various biogeochemical processes, responsible for As mobilization, is very important to explain this patchy occurrence and thus to mitigate the problem. The present study deals with the periodical monitoring of groundwater quality of five nested piezometeric wells between December 2008 and July 2009 to investigate the temporal changes in groundwater chemistry vis-a-vis the prevalent redox processes in the aquifer. Geochemical modeling has been carried out to identify key phases present in groundwater. A correlation study among different aqueous redox parameters has also been performed to evaluate prevailing redox processes in the aquifer. The long term monitoring of hydrochemical parameters in the multilevel wells together with hydrogeochemical equilibrium modeling has shown more subtle differences in the geochemical environment of the aquifer, which control the occurrence of high dissolved As in BDP groundwater. The groundwater is generally of Ca-HCO3 type. The dissolved As concentration in groundwater exceeded both WHO and National drinking water standard (Bureau of Indian Standards; BIS, 10 mu g L-1) throughout the sampling period. The speciation of As and Fe indicate persistent reducing conditions within the aquifer [As(III): 87-97% of As-T and Fe(II): 76-96% of Fe-T]. The concentration of major aqueous solutes is relatively high in the shallow aquifer (wells A and B) and gradually decreases with increasing depth in most cases. The calculation of SI indicates that groundwater in the shallow aquifer is also relatively more saturated with carbonate minerals. This suggests that carbonate mineral dissolution is possibly influencing the groundwater chemistry and thereby controlling the mobilization of As in the monitored shallow aquifer. Hydrogeochemical investigation further suggests that Fe and/or Mn oxyhydroxide reduction is the principal process of As release in groundwater from deeper screened piezometric wells. The positive correlations of U and V with As. Fe and Mn indicate redox processes responsible for mobilization of As in the deeper screened piezometric wells are possibly microbially mediated. Thus, the study advocates that mobilization of As is depth dependent and concentrations of As in groundwater depends on single/combined release mechanisms.

  • 271.
    Björkman, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Stabilitetsberäkningar och åtgärdsförslag vid islast på Skålandammen2005Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Hydropower is an important source of energy in Sweden and accounts for about 46 % of the total energy production. Sweden has about 1 200 hydropower plants and with the intention of raising the pressure head of the water and to store water, dams are built by the power plants. The storage reservoirs make it possible to adjust the energy production by demand and season. Dams in connection to the reservoirs are subjected to additional loading during periods of high floods or when an icecap in the winter is formed on the reservoirs. In order to maintain the dam safety, the power companies in Sweden are working with guidelines for dam safety from RIDAS. An important part of the work of dam safety is FDU that is carried out with purposes of improving the work of dam safety. A FDU made for the Skålan dam in the River of Ljungan showed that the levels of the safety factors for sliding and overturning of the dam was not fulfilled when subjected to loads from an icecap. The object of this thesis was to follow up the FDU and by carrying out extensive stability calculations on all parts of the Skålan dam, investigate what safety factors the different parts will get and also investigate some proposal measures in order to increase the dam stability.

    The stability calculations for the dam have been performed according to directions in RIDAS at four loading cases. Loading case I and II means a water level to the retained water level and an ice load of 200 and 100 kN/m respectively. Loading case III and IV means a situation without ice load but with a water level to the retained water level respectively a water level to a meter above the retained water level. The stability of the dam was studied with regards to sliding and overturning. The results from the stability calculations showed for both loading case I and II that the majority of the parts of the Skålan dam did not fulfill the levels of the safety factors. The calculations also showed that some parts of the dam did not fulfill the stability criteria of sliding at loading case III, which implies that these parts of the dam actually have not enough weight.

    The measure proposals studied were the ice preventive measures IR-elements and circulation of the deep warm water and the stability increasing measure with pre strained rock anchorages. The net present value (NVP) for the different measures were calculated with a life length of the dam estimated to 60 years. The results from the calculations of the NVP showed that the most economically feasible measure is circulation of the water but when considering the results from the stability calculations, the most suitable measure is the rock anchorages. Therefore, a combination of rock anchorages on parts which not fulfills the stability criteria in combination with circulation of the water is suggested to be the best measure.

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  • 272.
    Björnfot, Mikael
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    COMPUTATIONAL FLUID DYNAMICS MODELING FOR BENT SPILLWAY CHANNEL: Numerical validation of a small scale physical model2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Hydropower plants with spillways exposed to high pressures because of large discharges can result in a dam failure which ultimately results in devastating consequences. Therefore properly designed and constructed spillways are important. In this project there is an interest in examining the pressure distribution on a guided wall, measuring the water level inside the spillway and examine the water flow characteristics. The main purpose was to numerically model the flow behaviors at two upper pool levels +29.82 m and +30.92 m in order to achieve a comparison between a numerical model and a physical model.

    A previous experiment was carried out at Vattenfall R&D in Älvkarleby where a physical model was built. The main purpose of that study was to find an optimal form of a guide wall for free weir flow. This study served as guidelines for what should be investigated in this project.

    The methodology of the project began with a development of an initial CAD model created by Vattenfall R&D. The CFD model could be constructed into a volume model containing also an upstream reservoir. Next, a mesh that could numerically calculate the flow behavior was created in order to enable execution of the calculations. Furthermore, a big part of the method was to adjust the settings in Fluent so that the numerical model could recreate the flow behaviors of the physical model tests. The results indicate that the numerical model is an accurate replica of the physical model. The deviation comprising the mass flow rate came as close as 0.6 % from the physical model for the lower upper pool level. Highest calculated pressure was positioned at the bottom of the guided wall for both upper pool levels, which the results conducted from the physical model also indicated. Furthermore, results regarding the water level at the guided wall confirmed same statement Vattenfall's examinations pointed out, that the roof placed at the guided wall is needed in order to avoid major splashing.

    The present project has shown great results regarding the flow characteristics, pressure distribution, and the water level at the guided wall. Therefore, it is considered trustworthy enough to be used as a tool for Vattenfall R&D in future studies comprising the targeted spillway.

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  • 273.
    Blecken, Godecke
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Beryani, Ali
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Al-Rubaei, Ahmed
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Goldstein, Alisha
    North Carolina State University, USA.
    Hunt, William F.
    North Carolina State University, USA.
    Översiktlig utvärderingav funktionaliteten av 26 dagvattenbiofilter2021Other (Other academic)
    Abstract [sv]

    Implementering av dagvattenbiofilter i Sverige har ökat de senaste åren. Dock har det länge saknats dimensioneringsriktlinjer och filtrens utformning, dimensionering och konstruktion visar stora skillnader. Denna studie har på en översiktlig nivå undersökt funktionen och tillstånd av 26 svenska dagvattenbiofilter som har byggts mellan 2012 och 2019. Utifrån observationerna har vi sammanställt "typiska fel" och rekommenderar åtgärder för att förbättra funktionen. Syften med anläggningarna har jämförts med observationerna. Resultaten visar att många anläggningar har potential att uppfylla de uppsatta målen.

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  • 274.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Biofiltration technologies for stormwater quality treatment2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Due to high runoff volumes and peak flows, and significant contamination with (inter alia) sediment, metals, nutrients, polycyclic aromatic hydrocarbons and salt, urban stormwater is a major cause of degradation of urban water ways. Since current urban drainage systems, which heavily rely on piped sewer networks, may not be sustainable, attempts are being made to develop and refine sustainable urban drainage solutions, notably in Water Sensitive Urban Design (WSUD) and Low Impact Development (LID) concepts. Promising systems recommended for application in both WSUD and LID are stormwater biofilters (also known as bioretention systems or rain gardens) using vegetated filter media. Besides their capacity to attenuate flows and minimise runoff volumes, stormwater biofilters have proven efficacy for enhancing effluent water quality. Furthermore, they can be aesthetically pleasingly integrated even in dense urban environments. However, there are still gaps in our knowledge of the variability of biofilters' pollutant removal performance, and the factors that affect their performance.In the studies this thesis is based upon, the effects of various ambient factors, stormwater characteristics and modifications of filter design on the removal of metals, nutrients and total suspended solids (TSS) in biofilters, and pollutant pathways through them, have been investigated. For these purposes, standard biofilters and variants equipped with a submerged zone, a carbon source and different filter materials were exposed to varying temperatures and dry periods, dosed with stormwater and snowmelt, and the inflow and outflow concentrations of the pollutants were measured.Although removal percentages were consistently high (>70%), demonstrating that biofilters can reliably treat stormwater, the results show that metal outflow concentrations may vary widely depending on the biofilter design and the ambient conditions. Prolonged drying especially impaired their removal efficiency, but variations in temperature and filter media variations had little effect on metal removal rates. The adverse effects of drying could be mitigated by using a submerged zone, and thus providing a more constant moisture regime in the filters between storm events. Combined with embedded organic matter, the submerged zone especially significantly enhances Cu removal, helping to meet outflow target concentrations. Similarly, installing a mulch layer on top of the filter provides additional sorption capacity, hence metals do not ingress far into the filter and are mainly trapped on/in the top layer by sorption processes and/or mechanical trapping associated with TSS. This leads to significant metal accumulation, which facilitates biofilter maintenance since scraping off the top layer removes high proportions of previously accumulated metals, thus delaying the need to replace the whole filter media. However, removal of accumulated pollutants from the filter media is crucial for successful long-term performance of the filters to ensure that no pollutant breakthrough occurs.Nitrogen removal was found to be more variable than metal removal, and to be adversely affected by temperature increases, leading to high nitrogen leaching in warm temperatures. Phosphorus removal rates were consistently high, since most phosphorus was particle-bound and thus trapped together with TSS. However, in initial stages phosphorus was washed out from the filter media, indicating that filter media that do not have high levels of labile phosphorus should be used to avoid high effluent concentrations. Given that most outflow concentrations were far lower than those in the stormwater, biofilters are appropriate stormwater treatment systems. Dependent on the ambient conditions, the target pollutants and the sensitivity of the recipient, adaptation of the filter design is recommended. Further work is required to investigate the winter performance and improve the reliability of nitrogen removal, which is highly variable.

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  • 275.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hunt, William F.
    Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh.
    Al-Rubaei, Ahmed
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Lord, William G.
    North Carolina Cooperative Extension, North Carolina State University, Raleigh.
    Stormwater control measure (SCM) maintenance considerations to ensure designed functionality2017In: Urban Water Journal, ISSN 1573-062X, Vol. 14, no 3, p. 278-290Article in journal (Refereed)
    Abstract [en]

    Great investment is made in the design and installation of stormwater control measures (SCMs). Substantial research investment, too, is made to optimise the performance of SCMs. However, once installed, SCMs often suffer from lack of maintenance or even outright neglect. Key maintenance needs for wet ponds, constructed stormwater wetlands, bioretention, infiltration practices, permeable pavement, swales, and rainwater harvesting systems are reviewed with many tasks, such as the cleaning of pre-treatment areas and the preservation of infiltration surfaces, being common maintenance themes among SCMs. Consequences of lacking maintenance are illustrated (mainly insufficient function or failure). Probable reasons for neglect include insufficient communication, unclear responsibilities, lack of knowledge, financial barriers, and decentralised measures. In future designs and research, maintenance (and lack thereof) should be considered. Assessing the performance of SCMs conservatively and including safety factors may prevent consequences of under-maintenance; and requiring regular inspection may help to enforce sufficient maintenance.

  • 276.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Karlsson, Kristin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Closure to “Environmental Risk Assessment of Sediments Deposited in Stormwater Treatment Facilities: Trace Metal Fractionation and Its Implication for Sediment Management”2018In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 144, no 4Article in journal (Other academic)
  • 277.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Marsalek, Jiri
    National Water Research Institute, Environment Canada.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Laboratory study of stormwater biofiltration in low temperatures: total and dissolved metal removal and fates2011In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 219, no 1-4, p. 303-317Article in journal (Refereed)
    Abstract [en]

    Stormwater biofilters, which are recommended for application in both Water-Sensitive Urban Design and Low Impact Development, can remove up to 80% or 90% of total metals found in stormwater. However, their winter operation is a common concern. That was addressed in this study by investigating the metal removal effectiveness of replicate laboratory biofilter mesocosms at 2°C, 8°C and 20°C. As recommended for cold climate bioretention, coarse filter media were implemented and in the top 100 mm layer topsoil was added to increase the sorption capacity. Cd, Cu, Pb and Zn concentrations measured in the biofilter effluent were far below those in the influent and this significantly improved the treated stormwater quality. Contrary to a common notion that coarse media in the main filter body impair dissolved metal sorption, satisfactory removals of dissolved metals were found in this study with most metal burdens retained in the top layer of the filter in which the sorption capacity was enhanced by topsoil. Some metal uptake by the plants was also detected. Temperature did not affect Cd, Pb and Zn removals in general, but Cu removals increased with decreasing temperatures. This was explained by increased biological activities in the filters at warmer temperatures, which may have led to an increased release of Cu with dissolved organic matter originating from root turnover and decomposition of organic litter and debris. Furthermore, plant uptake and biofilm adsorption may also be influenced by temperature. However, even in the worst case (i.e. at 20°C), Cu was removed effectively from the stormwater. Further research needs were identified including the effects of road salts on stormwater biofiltration during the winter period.

  • 278.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Nordqvist, Kerstin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Søberg, Laila
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Dataset on stormwater bioretention column studies: Impact of temperature, salt and a submerged zone on the removal of metals, nutrients and suspended solids2022Data set
    Abstract [en]

    This data set presents the full raw data from bioretention column studies conducted at Luleå University of Technology in 2010-2014. The pilot scale columns were watered with synthetic stormwater. Influent and effluent samples were collected and analysed for pollutants including total and dissolved metals, nutrients, pathogens and suspended sediment. Further, supporting parameters (e.g. pH, conductivity) are included. The data enables quantifying the impact of bioretention design factors (submerged zone) and ambient factors (salinity in stormwater inflow, temperature) on the removal of these pollutants by bioretention. All filters utilised the same general column design and filter material as well as stormwater preparation. This enables inter-comparability between the different studies. Synthetic stormwater inflow concentrations and bioretention effluent concentrations are presented in the data set. Further, metal concentrations in the filter material and plant tissue have been analysed. The data set enables further analyses of bioretention performance, comparison with similar work performed elsewhere and can be used in modelling of bioretention removal performance and processes. Scientific papers describing the data have been published (see Publications)

  • 279.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Rentz, Ralf
    Malmgren, Charlotte
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Stormwater impact on urban waterways in a cold climate: variations in sediment metal concentrations due to untreated snowmelt discharge2012In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 12, no 5, p. 758-773Article in journal (Refereed)
    Abstract [en]

    Purpose: Stormwater discharges include contaminated sediments that accumulate in the receiving water body. It is thus important to investigate sediment and pollutant processes and pathways from the catchment to, and within, the receiving water. These processes may be influenced by seasonal changes. The objective of this study was to investigate the stormwater impact on receiving waters in the Luleå area, Northern Sweden; seasonal changes in contamination loads in the receiving waters due to snowmelt; and factors influencing the pollutant pathways in the receiving waters. Materials and methods: In front of three storm sewer outlets in Luleå, samples of bottom sediment (surface layer 0-2 cm) were collected from the connecting ditches and the downstream water body in autumn and spring (before and after the snow season 2009/2010). The characteristics of the receiving waters differed in geomorphology and vegetation. The sediment was analyzed for loss-on-ignition (LOI), grain size, and bulk concentrations of SiO 2, Al 2O 3, CaO, Fe 2O 3, MnO, Na 2O, P 2O 5, TiO 2, As, Cd, Co, Cr, Cu, Hg, Ni, Pb, S, V, and Zn. The sediment contamination was compared to concentrations at a reference point in Luleå where the bottom sediment was not affected by stormwater discharges and with Swedish environmental quality guidelines. Pearson's correlation and a principal component analysis were used to further evaluate the results. Results and discussion: Relative to the reference point, elevated trace metal concentrations were detected in sediments at all three sampling stations. At two of the stations, seasonal variations in ditch sediment grain size, LOI, and contaminant concentrations were observed, originating from stormwater sediment. Snowmelt runoff caused an increased proportion of fine-grained sediment fractions (<0.063 mm) in spring, mainly due to changes in runoff intensity and high sediment loads in the snowmelt runoff. The retention of metals appeared to be due to low turbulence in the water and the presence of organic material. Conclusions: Stormwater discharge affected the contaminant concentrations in the bottom sediments. The observed seasonal variation of contaminants indicated that relatively high amounts of contaminants are discharged during snowmelt and then reallocated within the receiving water body, either directly or after some temporal retention, depending on the characteristics of the receiving water. A calm water column and the presence of organic material in the receiving water body were crucial for the retention of metals

  • 280.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Tondera, Katharina
    Stormwater Research Group, University of the Sunshine Coast, Maroochydore.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Metals: Occurrence, Treatment Efficiency and Accumulation Under Varying Flows2018In: Ecotechnologies for the Treatment of Variable Stormwater and Wastewater Flows / [ed] Katharina Tondera, Godecke-Tobias Blecken, Florent Chazarenc, Chris C. Tanner, Cham: Springer, 2018, p. 75-91Chapter in book (Refereed)
    Abstract [en]

    Metals were the first priority pollutants to be widely investigated in stormwater. In solid phase, they are often attached to very fine particles. The dissolved fraction creates considerable environmental problems as it is the most bioavailable fraction. Hence, removal of both fine and dissolved particles plays a major role in the treatment of polluted runoff. Ecotechnologies specifically designed to remove metals should be able to address different treatment mechanisms. However, the exhaustion of sorption capacity reduces the lifespan of treatment facilities. Additionally, metal concentrations fluctuate extremely—spatially, seasonally and over time—which poses another challenge for further increasing removal efficiencies. While soil- or sand-based systems should be designed in a way that the filter material can be exchanged, newer developments such as Floating Treatment Wetlands show promising removal capacities as the installations bind metals in sludge sediments, which can be removed from time to time. The different treatment mechanisms, aforementioned developments and techniques as well as their removal capacities will be discussed in this chapter

  • 281. Blecken, Godecke-Tobias
    et al.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Muthanna, Tone M.
    Norwegian University of Science and Technology (NTNU), Trondheim.
    Zinger, Yaron
    Monash University, Melbourne, VIC.
    Deletic, Ana
    Monash University, Melbourne, VIC.
    Fletcher, Tim
    Monash University, Melbourne, VIC.
    Biofilter treatment of stormwater: temperature influence on the removal of nutrients2007In: Techniques et stratégies durables pour la gestion des eaux urbaines par temps de pluie: 6e Conférence internationale, [25-27] juin 2007, Lyon, France, Villeurbanne: Graie , 2007Conference paper (Refereed)
    Abstract [en]

    Nutrients can cause eutrophication of natural water bodies. Thus, urban stormwater which is an important nutrient source has to be treated in order to reduce its nutrient loads. Biofilters which use media, biofilms and plants, are a good treatment option regarding nutrients. This paper presents the results of a biofilter column study in cold temperatures (+2°C, +8°C, control at +20°C) which may cause special problems regarding the biofilter performance. It was shown that particle bound pollutants as TSS and a high fraction of phosphorus were reduced well without being negatively influenced by cold temperatures. Nitrogen, however, was not reduced; especially NOx was produced in the columns which can be explained with both insufficient denitrification and high leaching from the columns.

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  • 282. Blecken, Godecke-Tobias
    et al.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Svensson, Gilbert
    Hedström, Annelie
    Fat, oil and grease (FOG) in sewer systems: a significant problem in Sweden and Norway2009Conference paper (Other academic)
  • 283.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Svensson, Gilbert
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Fett i avloppsnät: kartläggning och åtgärdsförslag2010Report (Other academic)
    Abstract [en]

    Fat oil and grease (FOG) from food preparation can cause severeproblems if it is discharged to the municipal sewer network. A surveyamong Swedish and Norwegian municipalities has shown that nearlyall respondents experience FOG-related problems. The most commonproblem is FOG accumulation connected to the sewer pipes whichdecreases the pipe pipe capacity and may lead to sewer overflows. FOGaccumulation occurs especially at lift stations and depressions. FOGdeposits are often made up of saponised FOG. The fatty acids promotefurthermore corrosion of concrete pipes. FOG can even impact wastewater treatment and might cause severer working conditions.The aim for the water suppliers has thus to be an effective FOGsource control before FOG is discharged to the sewer network. Sourcesare both commercial establishments and residential sewer customers.In this report different source control measures are discussed. Greaseinterceptors are commonly used for commercial FOG sources. However,a number of them lack a grease interceptor and quite often operationand maintenance is deficient. An insufficient frequency ofemptying and a lack of supervision have been identified as a commonproblem. FOG collection systems for commercial FOG producers existin both Sweden and Norway. Collection systems for private householdsare currently in a test phase and experiences from among others Austriaare promising. Even the collected amount of FOG could presumablybe increased. Collected FOG and FOG slurry from interceptors is avaluable resource which can be used as raw material in the chemicalindustry or as an energy source (combustion, biodiesel, fermentation).Threshold values for FOG discharges are set up commonly by municipalities.However, even here supervision is often insufficient. Often, thethreshold values are inadequately low and a value of at least 150 mg/lis recommended. All those measures have to be supported by informationcampaigns which aim on both commercial and private customers.

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  • 284.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Svensson, Gilbert
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hedström, Annelie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Projekt: Fett i avloppsnät - Kartläggning och åtgärdsförslag2010Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Matfett och -olja som släpps ut till avloppsnätet kan orsaka driftproblem. Denna enkätstudie har visat att nästan alla kommuner i Norge och Sverige upplever problem på grund av fettet.

  • 285.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Zinger, Yaron
    Monash University, Melbourne, VIC.
    Deletic, Ana
    Monash University, Melbourne, VIC.
    Fletcher, Tim D.
    Monash University, Melbourne, VIC.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Effect of retrofitting a saturated zone om the performance of biofiltration for heavy metal removal: preliminary results of a laboratory study2010In: NOVATECH 2010: 7th International conference on sustainable techniques and strategies in urban water management, Lyon, France, June 27 - July 1st, 2010, Villeurbanne: Graie , 2010Conference paper (Refereed)
    Abstract [en]

    Stormwater biofilters are a stormwater treatment technology which has been becoming increasingly popular. Recently it has been shown that a submerged zone in the filter media improves the magnitude and consistency of nitrogen treatment. Furthermore, the submerged zone has even been shown to be beneficial for retention of heavy metals, particularly Cu. However, most existing biofilters do not include a saturated zone. Since it is relatively simple to retrofit a submerged zone by elevating the outflow, the effect of such a retrofitting on metal removal was investigated in this laboratory study using biofilter columns. It has been shown that a retrofitted submerged zone has a statistically significant but practically small effect on metal removal: Zn removal is slightly enhanced while the effect on Cu removal is inconsistent. Thus, retrofitting of a submerged zone is not recommended if metals are the main target pollutants. But if a submerged zone would have other benefits (e.g. for nitrogen removal or to protect the system from prolonged drying periods) it can be retrofitted without compromising metal removal.

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  • 286. Blecken, Godecke-Tobias
    et al.
    Zinger, Yaron
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Deletic, Ana
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Fletcher, Tim D.
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Impact of a submerged zone and a carbon source on heavy metal removal in stormwater biofilters2009In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 35, no 5, p. 769-778Article in journal (Refereed)
    Abstract [en]

    Biofilters are an effective treatment option for the substantial heavy metal loads in urban stormwater. However, to increase their nitrogen treatment efficacy, the introduction of a submerged (anoxic) zone (SZ) and a cellulose based carbon source (C) has been recommended because it has been shown to enhance denitrification and thereby increase overall nitrogen removal. To examine the impact of this design modification on heavy metal treatment, a laboratory study using biofilter mesocosms with different levels of SZ and with or without added C was conducted. The results show that SZ and C have a significant impact on metal treatment. In particular, the removal of Cu was improved significantly. The presence of SZ and C allows outflow Cu concentrations to meet Swedish and Australian water quality guidelines, which are not met with a standard biofilter without SZ or C. Although Zn and Pb removal was enhanced slightly by the presence of a SZ, this improvement is of less practical importance, since Zn and Pb removal is already very high (>95%) in standard biofilters. The best metal treatment was achieved with 450 and 600 mm SZ. Based on these results, the incorporation of SZ with C in stormwater biofilters is recommended.

  • 287.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Zinger, Yaron
    Monash University, Melbourne, VIC.
    Deletic, Ana
    Monash University, Melbourne, VIC.
    Fletcher, Tim D
    Monash University, Melbourne, VIC.
    Viklander, Maria
    Laboratory studies on metal treatment efficiency of stormwater biofilters2010Conference paper (Other academic)
    Abstract [en]

    Stormwater biofilters are a reliable technology to remove metals from stormwater. A solid carbon source in the filter (combined with a submerged zone) enhances especially Cu removal further; the already high Pb and Zn removal is slightly enhanced. However, the submerged zone helps to minimize (Cu, Zn) or eliminate (Pb) the negative effects which prolonged drying has on the removal rates. Thus, the introduction of a submerged zone is only recommended if nitrogen treatment is targeted (Zinger et al. 2007) or if drying is expected. Temperature differences might have a little influence on especially Cu treatment. However, this influence is not of practical importance indicating that biofilters can successfully be implemented throughout the whole seasonal cycle. A high proportion of metals are retained at the top of the filter which is important for biofilter design and maintenance planning. A filter less than the currently recommended 800 to 900 mm might be sufficient for reliable metal treatment. Furthermore, scraping of the top layer could delay replacing of the whole filter media

  • 288.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Zinger, Yaron
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Deletic, Ana
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Fletcher, Tim
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Hedström, Annelie
    Viklander, Maria
    Laboratory study on stormwater biofiltration: nutrient and sediment removal in cold temperatures2010In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 394, no 3-4, p. 507-514Article in journal (Refereed)
    Abstract [en]

    Stormwater biofilters have the ability to remove nutrients from stormwater. Reliable pollutant removal during the cold season is particularly important due to the comparably high contamination levels. However, the removal performance might be negatively affected by low temperatures. A biofilter column study was conducted in thermostat-controlled climate rooms (at 2, 7 and 20 °C) to investigate the effect of low temperatures on nutrient removal. Phosphorus and suspended solids removal were significantly correlated and consistently very high (typically in excess of 90 and 95%, respectively, at all temperatures). This is important for the successful implementation of biofilters in cold climates since phosphorus is commonly of principal concern, often being the limiting factor for eutrophication in freshwater ecosystems. Unfortunately, nitrogen removal was poor and leaching was shown, which increased with temperature. The increasing nitrate-nitrogen production rates with temperature were well described by the Arrhenius relationship with temperature coefficients Q10 in the range which is typically used to describe temperature effects on nitrification. Thus, temperature effects have to be considered when nitrogen removal is targeted and the biofilter might be exposed to cold temperatures.

  • 289. Blecken, Godecke-Tobias
    et al.
    Zinger, Yaron
    Monash University, Melbourne, VIC.
    Deletic, Ana
    Monash University, Melbourne, VIC.
    Fletcher, Tim
    Monash University, Melbourne, VIC.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Heavy metal removal by stormwater biofilters: can it withstand alternative drying and wetting conditions?2008In: Conference Proceedings : 11th International Conference on Urban Drainage: Edinburgh International Conference Centre, Scotland : 11 ICUD: 31st August - 5th September 2008, Munich: Oldenbourg Industrieverlag , 2008Conference paper (Refereed)
    Abstract [en]

    Urban stormwater contains substantial loads of Cu, Pb and Zn, which are considered as key stormwater contaminants. Stormwater biofiltration is a promising option to treat these contaminants. Biofilters are exposed to an alternate cycle of drying and wetting, and the influence of this on pollutant removal performance is as-yet unknown. To investigate the effect of drying and subsequent rewetting on the retention of heavy metals by stormwater biofilters, a laboratory study has been conducted using three groups of biofilter columns, which were dosed with semi-synthetic stormwater according to three different drying and wetting regimes. Some biofilters were fitted with a submerged zone combined with a carbon source, at the bottom of the filter. Overall, the biofilters were very effective in heavy metal removal, provided that they received regular stormwater input. However, after drying extending to three or four weeks, removal of heavy metals decreased significantly. A statistically significant correlation between antecedent dry days and metal removal was shown. Furthermore, a clear effect of the submerged zone was found: after extended dry periods, biofilters with this feature performed significantly better than those without it. In particular, the removal of Cu was clearly increased both during wet and dry periods; for Pb the negative effect of drying was completely eliminated by introducing a submerged zone.

  • 290. Blecken, Godecke-Tobias
    et al.
    Zinger, Yaron
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Deletic, Ana
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Fletcher, Tim
    Facility for Advancing Water Biofiltration, Department of Civil Engineering, Monash University.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Influence of intermittent wetting and drying conditions on heavy metal removal by stormwater biofilters2009In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 43, no 18, p. 4590-4598Article in journal (Refereed)
    Abstract [en]

    Biofiltration is a technology to treat urban stormwater runoff which conveys pollutants, including heavy metals. However, the variability of metals removal performance in biofiltration systems is as yet unknown.A laboratory study has been conducted with vegetated biofilter mesocosms, partly fitted with a submerged zone at the bottom of the filter combined with a carbon source. The biofilters were dosed with stormwater according to three different dry/wet schemes, to investigate the effect of intermittent wetting and drying conditions on metal removal.Provided that the biofilters received regular stormwater input, metal removal exceeded 95%. The highest metal accumulation occurs in the top layer of the filter media.However, after antecedent drying before a storm event exceeding three to four weeks the filters performed significantly worse, although metal removal still remained relatively high. Introducing a submerged zone into the filter improved the performance significantly after extended dry periods. In particular, copper removal in filters equipped with a submerged zone was increased by around 12% (α = 0.05) both during wet and dry periods and for lead the negative effect of drying could completely be eliminated, with consistently low outflow concentrations even after long drying periods.

  • 291. Blecken, Godecke-Tobias
    et al.
    Zinger, Yaron
    Monash University, Melbourne, VIC.
    Muthanna, Tone M.
    Norwegian Institute for Water Research (NIVA), Trondheim.
    Deletic, Ana
    Monash University, Melbourne, VIC.
    Fletcher, Tim D.
    Monash University, Melbourne, VIC.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    The influence of temperature on nutrient treatment efficiency in stormwater biofilter systems2007In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 56, no 10, p. 83-91Article in journal (Refereed)
    Abstract [en]

    Nutrients can cause eutrophication of natural water bodies. Thus, urban stormwater which is an important nutrient source in urbanised areas has to be treated in order to reduce its nutrient loads. Biofilters which use soil filter media, biofilms and plants, are a good treatment option for nutrients. This paper presents the results of a biofilter column study in cold temperatures (+2 °C, +8 °C, control at +20 °C) which may cause special problems regarding biofilter performance. It was shown that particle-bound pollutants as TSS and a high fraction of phosphorus were reduced well without being negatively influenced by cold temperatures. Nitrogen, however, was not reduced; especially NOx was produced in the columns. This behaviour can be explained with both insufficient denitrification and high leaching from the columns

  • 292.
    Blekic, Demir
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Fritz, Adam
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Förslag på generell arbetsprocess för utredningar av befintliga dagvattendammar ur ett funktionellt perspektiv2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: At present are new stormwater ponds constructed to store stormwater which overloads stormwater pipe systems while existing stormwater ponds remains without overhaul. Since climate changes contributes to five-year rain in a higher frequency, which increases the flow of stormwater and causing more stormwater ponds to be undersized. In order to preserve social functions, are a general work process investigated of how municipalities can investigate and preserve their existing stormwater ponds. Method: The methods that are used are interviews, case study and literature study. The interviews contribute to solutions and proposals of investigation methods and proposals for action. The case study were performed in three stormwater ponds and examines the investigation methods that can be used. Collecting empirical data in a practical case, should increase the investigation’s credibility. The methods used in the case study are calculations, sediment sampling and document analysis of the basis of existing stormwater. Using literature study are the empirical data of the investigation analyzed with other sources to check the reliability of the empirical data. Findings: Several methods of investigations and action proposals were analyzed. Three investigation methods which fit a general work process were: flow proportional sampling, sediment sampling and stormwater calculations through the stormwater model Stormtac. The proposals for action which suited a general work process were: construction of a trench around the pond to expand the storage area, planting plants that take up nutrients and heavy metals tied up in stormwater, exploit the stormwater ponds shape where the hydraulic efficiency are exploited flat out by placing the inlet and outlet on opposite ends, and building trenches with a gravel embankment with aquatic plants. Implications: Flow proportional sampling were a reliable investigation method according to interview and literature study. Sediment sampling of sediment in bottom of in- and outlet can be used in a general work process, but certain contamination levels can be misleading depending on how detailed sediment samplings are done. Stormwater model Stormtac and its calculations can be used in a general workprocess because publication Svenskt Vatten P110 (2016) are confirming the models calculations. The proposals for action were not tested in real cases, but the effect was confirmed in the interview and literature study. Limitations: The case study was limited by investigating two methods, one of which is stormwater model Stormtac and sediment sampling. Selected contaminants such as heavy metals, oil, nitrogen and phosphorus are analysed. The study is delimitated by analyzing how recipients are affected by the studied existing stormwater ponds.

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  • 293.
    Blennow, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Återvinning av näringsämnen från hushållsspillvatten med omvänd osmos2005Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Hammarby Sjöstad is a new district in Stockholm with high environmental standard. Stockholm Water Company evaluates a local wastewater treatment plant with cutting edge technology. The first step is an experimental treatment plant (Sjöstadsverket) with four parallel lines of treatment, each with a capacity to treat wastewater from 150 persons. Within the membrane technology subproject the possibility of using reverse osmosis (usually called RO) to regain nutrients is examined.

    Reverse osmosis separates the incoming water in a clean permeate and a concentrate that, as the name indicates, is a more concentrated version of the incoming water. Using this method in wastewater treatment, a solution high in nutrients can be obtained without the use of chemical precipitation agent and with no production of sludge. The solution can then be recycled to use on farmland. The disadvantages of the RO technology include high energy consumption and sensitivity to membrane fouling.

    The aim of this study was to investigate the possibility of using RO at Sjöstadsverket and, if possible, to evaluate the chance of obtaining concentrate that can be accepted as a fertiliser and permeate that falls below emission limits. The experiments were carried out with an RO plant with three membranes in series operated in batch mode; the dimensioned permeate flow being 100 l/h. The incoming water was permeate from a membrane bioreactor in the majority of the trial runs.

    The results show that RO can be used in at least one of the lines of treatment. However the permeate exceeds the emission limits (phosphorus: 0,15 mg/l, nitrogen: 6 mg/l) while concentration in the concentrate is still too low. The limiting factor seems to be phosphorus. This could be solved with pre-precipitation of phosphorus or by reconstructing the RO plant to a two-stage system. The quota heavy metal – phosphorus in the concentrate is lower than the limit imposed by the Swedish Environmental Protection Agency but much higher than in human urine.

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  • 294.
    Blix, Annika
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Geochemistry and Ecotechnology.
    Enhancing the capacity of seeds as turbidity removal agents in water treatment.: A Minor Field Study.2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this master’s thesis was to investigate if defattening of Parkinsonia aculeata (in

    swahili “mkeketa”) and Vigna unguiculata (in swahili “choroko”) would enhance the capacity of the seed’s properties in removing suspended particles from surface water. The seeds are used in local traditional treatment of drinking water in Tanzania. The aim was also to investigate the possibility to reduce high concentrations of fluoride with the seeds. The seeds contain proteins that act as coagulants. Coagulated particulate matter can be flocculated and separated from the water. A purification of the coagulants by defattening was expected to enhance the coagulating capacity. Experiments were conducted in jar-tests with dosages of coagulant solutions of undefattening and defattened seed solutions and alum (aluminium sulphate). The experiments showed that both Parkinsonia aculeata and Vigna unguiculata seeds can compete with alum in drinking water treatment of surface water, reaching the same or better final results in turbidity removal. Both seeds also produce less sludge volumes than alum and functions in turbidity removal together with alum. The seeds may be used as coagulant aids to reduce the usage of chemicals and sludge production. They were not able to clarify turbid waste water and did not reduce high concentrations of fluoride in groundwater. Further, the turbidity-removal capacity of the coagulants had reduced capacities in water with low pH-values.

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  • 295.
    Blomberg, Johan
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Sörgårn, Alfred
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Lastkapacitet hos murar byggda med C3C blocksystem -översvämningslaster2021Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Floods are the natural disaster that causes the most deaths and economic damage in the world. Sweden has been relatively spared from casualties in connection with floods, but the material damage is significant. In the future, larger and more frequent floods are expected. It is therefore interesting to study new protection barriers with higher capacity. C3C Engineering AB is a Växjö-based company that manufactures concrete blocks according to the lego principle out of waste concrete. In 2021, C3C has 99 production sites spread around Sweden. In the study, four models of stacking C3Cblock® were analyzed.The aim of the study was to produce calculation materials that can be used for stacking and placing C3Cblock® for flood protections. To calculate the capacity of the models, three horizontal loads were assumed to act on the stacking: static water pressure, hydrodynamic water pressure and floating debris load. In the study, four interviews with experts in the flood area were conducted. The interviews provided an insight into how experts at the relevant authorities view Sweden's preparedness, management, planning against floods and which criteria for protection barriers are considered important.The results from the study show that the C3Cblock® largely manage the water velocities and water heights that the authority for protection and preparedness maps for. The work also shows that the impact of floating debris has a relatively small effect compared to the hydrodynamic and hydrostatic water load. As the calculation set-up has been in ideal conditions, it is important when using the C3Cblock® for flood prevention purposes to have knowledge of terrain conditions such as base material and ground slope.

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  • 296.
    Blomkvist, Pär
    et al.
    Division of Organization and Management, Mälardalen University, Högskoleplan 1, 722 20, Västerås, Sweden.
    Karpouzoglou, Timon
    KTH, School of Architecture and the Built Environment (ABE), Philosophy and History, History of Science, Technology and Environment.
    Nilsson, David
    KTH, School of Architecture and the Built Environment (ABE), Philosophy and History, History of Science, Technology and Environment.
    Wallin, Jörgen
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Entrepreneurship and alignment work in the Swedish water and sanitation sector2023In: Technology in society, ISSN 0160-791X, E-ISSN 1879-3274, Vol. 74, article id 102280Article in journal (Refereed)
    Abstract [en]

    Water and sewage (WS) systems are, like most grid based infrastructural systems, often centralised and hierarchical and the end user has almost no possibility to influence the technical standards, business models or system architecture. The preferred method for connecting new areas to the grid are underground water pipes and gravity flow for sewage. Thus, the WS system is “tightly coupled”. It is hard to change and conservative in its system culture, exhibiting a strong “momentum” or “path dependence”. In this article we investigate an unusual case in the development of WS-systems. As a rule, WS-systems, as most infrastructural systems, develop gradually through incremental innovations, and system owners/utilities traditionally build their systems “from the inside out”. In our case, we investigate a situation where the end users took the initiative to connect a residential area, Aspvik, part of the municipality of Värmdö, outside Stockholm, Sweden, to the municipal grid and thus expand the WS-system, not from the inside out, but from the outside in. Furthermore, we highlight another unusual feature: the role of a resident that acted as the “entrepreneur” in this process of WS-system expansion. The entrepreneur had unique trust building abilities in the local community, which the regime actor (the WS utility), could not match. Historically, inventor-entrepreneurs have been common, acting as “system builders” in the establishment phase of new infrastructural systems. However, entrepreneurs outside the regime are not common in the WS sector. Although atypical in mature WS systems in developed countries, these types of local initiatives or hybrid solutions are common in developing countries. In this article, we argue that there are lessons to be learnt from our case, when dealing with system expansion processes both inside and outside the Global North.

  • 297.
    Blomstrand, Patrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    Jemander, Rasmus
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    Systemteknisk studie av pumpstyrning på Henriksdals nya reningsverk2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The population of Stockholm is increasing and with it the amount of wastewater that needs treatment. To cope with the increase, Henriksdal wastewater treatment plant (WWTP) in Stockholm, Sweden, is currently being expanded into the worlds largest WWTP using membrane bioreactor (MBR) technology. The plant will be controlled to a greater extent by pumps and good control is therefore vital to maintain operational stability and an energy efficient process. To analyse the intricate system of pumps and equalisation in tunnels a dynamic model is required.One reason for expanding Henriksdal WWTP is the decommissioning of Bromma WWTP. Wastewater from Bromma will be diverted to Henriksdal through a large tunnel which can be used for flow equalization. To examine whether flow equalization in the tunnel can even out diurnal variations and extreme rain events, water flow in the tunnel and throughout the WWTP was modelled. Models of the tunnel, pumps and basins were made in the programming language C and then merged with different controllers in Matlab/Simulink. To simulate different scenarios for the year 2040, data for the rainy year of 2012 was increased to match the expected population for 2040.Based on simulations for a scenario with dry weather the possibility for flow equalization could be shown. It required a thought-out control strategy for the control of Bromma pumping station based on flow measurements from several other inflows to the WWTP. The control strategy also proved adequate in handling downpours by increasing the amount of waste water subjected to biological treatment. When simulating snow melt or heavy rain, damming in the Bromma tunnel could help to prevent overflow if no strict boundaries were used for the water level in the tunnel. With a maximum allowed water level of 10 m it was, however, possible to dam the first flush containing high concentrations of pollutants and nutrients.Flow equalization makes it easier to maintain even levels in the basins for the return activated sludge (RAS), which in turn makes it easier to maintain high levels in said basins. Higher levels in the RAS-basins leads to reduced energy consumption. In the event of further development of the model, it is possible to add calculations of energy usage for the pumps, which would facilitate further optimization of controllers and their parameters.

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  • 298.
    Blum, Kristin M.
    et al.
    Umea Univ, Dept Chem, S-90187 Umea, Sweden..
    Norström, Sara H.
    Umea Univ, Dept Chem, S-90187 Umea, Sweden..
    Golovko, Oksana
    Univ South Bohemia Ceske Budejovice, Fac Fisheries & Protect Waters, South Bohemian Res Ctr Aquaculture & Biodivers Hy, Zatisi 728-2, Vodnany 38925, Czech Republic..
    Grabic, Roman
    Univ South Bohemia Ceske Budejovice, Fac Fisheries & Protect Waters, South Bohemian Res Ctr Aquaculture & Biodivers Hy, Zatisi 728-2, Vodnany 38925, Czech Republic..
    Järhult, Josef D.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Infectious Diseases. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Koba, Olga
    Univ South Bohemia Ceske Budejovice, Fac Fisheries & Protect Waters, South Bohemian Res Ctr Aquaculture & Biodivers Hy, Zatisi 728-2, Vodnany 38925, Czech Republic..
    Söderström Lindström, Hanna
    Umea Univ, Dept Chem, S-90187 Umea, Sweden.;Umea Univ, Dept Publ Hlth & Clin Med, Occupat & Environm Med, S-90187 Umea, Sweden..
    Removal of 30 active pharmaceutical ingredients in surface water under long-term artificial UV irradiation2017In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 176, p. 175-182Article in journal (Refereed)
    Abstract [en]

    This study investigated the i) kinetics, and ii) proportion of photolysis of 30 relatively stable active pharmaceutical ingredients (APIs) during artificial UV irradiation for 28 d in ammonium acetate buffer, filtered and unfiltered river water. Buffer was included to control removal kinetics under stable pH conditions and without particulate matter. Dark controls were used to determine removal due to other processes than photolysis and calculate the proportion of photolysis of the total removal. The removal of each API in each matrix was determined using online solid phase extraction/liquid chromatography tandem mass spectrometry (online SPE/LC-MS/MS). Most APIs transformed during the 28 d of UV irradiation and the dark controls showed that photolysis was the major removal process for the majority of the APIs studied. The half-lives ranged from 6 h (amitriptyline) in unfiltered river water to 884 h (37 d, carbamazepine) in buffer. In unfiltered river water, the proportion of APIs with short half-lives (<48 h) was much higher (29%) than in the other matrices (4%), probably due to additional organic carbon, which could have promoted indirect photolysis. Furthermore, two APIs, memantine and fluconazole, were stable in all three matrices, while alprazolam was stable in buffer and unfiltered river water and four additional APIs were stable in buffer. Considering the relatively long-term UV-exposure, this study enabled the investigation of environmentally relevant half-lives in natural waters. Many APIs showed high persistence, which is environmentally concerning and emphasizes the importance of further studies on their environmental fate and effects.

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  • 299.
    Bobbert, Peter A.
    et al.
    Eindhoven University of Technology, Netherlands.
    Sharma, Abhinav
    Eindhoven University of Technology, Netherlands.
    Mathijssen, Simon G. J.
    Eindhoven University of Technology, Netherlands; Philips Research Labs, Netherlands.
    Kemerink, Martijn
    Eindhoven University of Technology, Netherlands.
    de Leeuw, Dago M.
    Philips Research Labs, Netherlands.
    Operational Stability of Organic Field-Effect Transistors2012In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 24, no 9, p. 1146-1158Article in journal (Refereed)
    Abstract [en]

    Organic field-effect transistors (OFETs) are considered in technological applications for which low cost or mechanical flexibility are crucial factors. The environmental stability of the organic semiconductors used in OFETs has improved to a level that is now sufficient for commercialization. However, serious problems remain with the stability of OFETs under operation. The causes for this have remained elusive for many years. Surface potentiometry together with theoretical modeling provide new insights into the mechanisms limiting the operational stability. These indicate that redox reactions involving water are involved in an exchange of mobile charges in the semiconductor with protons in the gate dielectric. This mechanism elucidates the established key role of water and leads in a natural way to a universal stress function, describing the stretched exponential-like time dependence ubiquitously observed. Further study is needed to determine the generality of the mechanism and the role of other mechanisms.

  • 300.
    Boberg, Björn
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Holm, David
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    FEM modeling of concrete gravity dams.2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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