The dynamic and complex municipal wastewater treatment plant (MWWTP) process should be handled efficiently to safeguard the excellent quality of effluents characteristics. Most of the available mathematical models do not efficiently capture the MWWTP process, in such cases, the data-driven models are reliable and indispensable for effective modeling of effluents characteristics. In the present research, two nonlinear system identification (NSI) models namely; Hammerstein-Wiener model (HW) and nonlinear autoregressive with exogenous (NARX) neural network model, and a classical autoregressive (AR) model were proposed to predict the characteristics of the effluent of total suspended solids (TSS_eff) and pH_eff from Nicosia MWWTP in Cyprus. In order to attain the optimal models, two different combinations of input variables were cast through auto-correla-tion function and partial auto-correlation analysis. The prediction accuracy was evaluated using three statistical indicators the determination coefficient (DC), root mean square error (RMSE) and correlation coefficient (CC). The results of the appraisal indicated that the HW model outperformed NARX and AR models in predicting the pH_eff, while the NARX model performed better than the HW and AR models for TSS_eff prediction. It was evident that the accuracy of the HW increased averagely up to 18% with regards to the NARX model for pH_eff . Likewise, the TSS_eff performance increased averagely up to 25% with regards to the HW model. Also, in the validation phase, the HW model yielded DC, RMSE, and CC of 0.7355, 0.1071, and 0.8578 for pHeff, while the NARX model yielded 0.9804, 0.0049 and 0.9902 for TSS_eff, respectively. For comparison with the traditional AR, the results showed that both HW and NARX models outperformed in (TSS_eff) and pH_eff prediction at the study location. Hence, the outcomes determined that the NSI model (i.e., HW and NARX) are reliable and resilient modeling tools that could be adopted for pH_eff and TSS_eff prediction.

Diyala River is the third largest tributary of the Tigris River running 445 km length and draining an area of 32,600 km2. The river is the major source of water supply for Diyala City for municipal, domestic, agriculture and other purposes. Diyala River Basin currently is suffering from water scarcity and contamination problems. Up-to-date studies have shown that blue and green waters of a basin have been demonstrating increasing variability contributing to more severe droughts and floods seemingly due to climate change. To obtain better understanding of the impacts of climate change on water resources in Diyala River Basin in near 2046~2064 and distant future 2080~2100, SWAT (soil and water assessment tool) was used. The model is first examined for its capability of capturing the basin characteristics, and then, projections from six GCMs (general circulation models) are incorporated  to assess the impacts of climate change on water resources under three emission scenarios: A2, A1B and B1. The results showed deteriorating water resources regime into the future.

Kurdistan in northern Iraq, a semi-arid region, predominantly a pastureland, is nourished by Lesser Zab, which is the second major tributary of Tigris River. The discharge in the tributary, in recent times, has been experiencing increasing variability contributing to more severe droughts and floods supposedly due to climate change. For a proper appreciation, SWAT model has been used to assess the impact of climate change on its hydrological components for a half-centennial lead time to 2046-2064 and a centennial lead time to 2080-2100. The suitability of the model was first evaluated, and then, outputs from six GCMs were incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A1B, A2 and B1. The results showed worsening water resources regime.

SWAT model (Sediment and Water Assessment Tool) was used to evaluate the impacts of climate change on water resources in Al-Adhaim Basin which is located in north east of Iraq. Al-Adhaim River is the main source of fresh water to Kirkuk City, one of the largest cities of Iraq. Recent studies have shown that blue and green waters of the basin have been manifesting increasing variability contributing to more severe droughts and floods apparently due to climate change. In order to gain greater appreciation of the impacts of climate change on water resources in the study area in near and distant future, SWAT (Soil and Water Assessment Tool) has been used. The model is first tested for its suitability in capturing the basin characteristics, and then, forecasts from six GCMs with about half-a-century lead time to 2046-2064 and one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A2, A1B and B1. The results showed worsening water resources regime into the future.

The Khabour River is one of five tributaries of Tigris River and the first river flows into Tigris River contributing to Tigris Flow by about 2 BCM at Zakho Station. The area of this catchment is 6,143 km2, of which 57% are located in Turkey and 43% in Iraq with a total length of 181 km. Khabour River is the main source of fresh water to Duhok City, one of the major cities of Kurdistan Region. Hydrometeorological data over the past several decades reveal that the catchment is experiencing increasing variability in precipitation and stream flow contributing to more severe droughts and floods presumably due to climate change. SWAT model was applied to capture the dynamics of the basin. The model was calibrated at Zakho station. The performance of the model was rather satisfactory; R2 and ENC were 0.5 and 0.51, respectively in calibration period. In validation process R2 and ENC were nearly consistent. In the next stage, six GCMs from CMIP3 namely, CGCM3.1/T47, CNRM-CM3, GFDL-CM2.1, IPSLCM4, MIROC3.2 (medres) and MRI CGCM2.3.2 were selected for climate change projections in the basin under a very high emissions scenario (A2), a medium emissions scenario (A1B) and a low emissions scenario (B1) for two future periods (2046-2064) and (2080-2100). All GCMs showed consistent increases in temperature and decreases in precipitation, and as expected, highest rate for A2 and lowest rate for B1. The projected temperatures and precipitation were input to the SWAT model to project water resources, and the model outputs were compared with the baseline period (1980-2010), the picture that emerged depicted deteriorating water resources variability.

This paper assesses water quality that is used for vegetable irrigation in Tamale Metropolis, Ghana. A mixed-method of research design was employed in this study to collect and analyze the data based on survey instruments. The paper found that Escherichia coli (E. coli) that is usually used as an indicator of water contamination and heavy metals exist in all taken water samples. The mean concentrations of nutrients such as ammonia, nitrate, nitrite and phosphate were recorded as 0.022 mg/l to 5.98 mg/l for ammonia, 1.06 mg/l to 7.52 mg/l for nitrate, 0.031 mg/l to 0.056 mg/l for nitrate and 0.037 mg/l to 0.069 mg/l for phosphate. E. coli and Total Coliforms levels for Sanghani, Kamina and Waterworks from the laboratory analysis were recorded as 3.2x10(3) CFU 100 m/l and 5.5x10(2) CFU 100 m/l, 4.0x10(3) CFU 100 m/l and 1x10(2) CFU 100 m/l, and 2.1x10(3) CFU 100 m/l and 4.6x10(2) CFU 100 m/l respectively. To conclude, based on the measured parameters, water used for irrigation in the Tamale Metropolitan is polluted and may cause potential health risks. Therefore, farmers, traders and consumers need to apply further safety measures to make the vegetables safe.

Precise assessment of water footprint to improve the water consumption and crop yield for irrigated agricultural efficiency is required in order to achieve water management sustainability. Although Penman-Monteith is more successful than other methods and it is the most frequently used technique to calculate water footprint, however, it requires a significant number of meteorological parameters at different spatio-temporal scales, which are sometimes inaccessible in many of the developing countries such as Egypt. Machine learning models are widely used to represent complicated phenomena because of their high performance in the non-linear relations of inputs and outputs. Therefore, the objectives of this research were to (1) develop and compare four machine learning models: support vector regression (SVR), random forest (RF), extreme gradient boost (XGB), and artificial neural network (ANN) over three potato governorates (Al-Gharbia, Al-Dakahlia, and Al-Beheira) in the Nile Delta of Egypt and (2) select the best model in the best combination of climate input variables. The available variables used for this study were maximum temperature (Tmax), minimum temperature (Tmin), average temperature (Tave), wind speed (WS), relative humidity (RH), precipitation (P), vapor pressure deficit (VPD), solar radiation (SR), sown area (SA), and crop coefficient (Kc) to predict the potato blue water footprint (BWF) during 1990–2016. Six scenarios (Sc1–Sc6) of input variables were used to test the weight of each variable in four applied models. The results demonstrated that Sc5 with the XGB and ANN model gave the most promising results to predict BWF in this arid region based on vapor pressure deficit, precipitation, solar radiation, crop coefficient data, followed by Sc1. The created models produced comparatively superior outcomes and can contribute to the decision-making process for water management and development planners. 

The limited amount of freshwater is the most important challenge facing Egypt due to increasing population and climate change. The objective of this study was to investigate how climatic change affects the winter potato water footprint at the Nile Delta covering 10 governorates from 1990 to 2016. Winter potato evapotranspiration (ETC) was calculated based on daily climate variables of minimum temperature, maximum temperature, wind speed and relative humidity during the growing season (October–February). The Mann–Kendall test was applied to determine the trend of climatic variables, crop evapotranspiration and water footprint. The results showed that the highest precipitation values were registered in the northwest governorates (Alexandria followed by Kafr El-Sheikh). The potato water footprint decreased from 170 m3 ton−1 in 1990 to 120 m3 ton−1 in 2016. The blue-water footprint contributed more than 75% of the total; the remainder came from the green-water footprint. The findings from this research can help government and policy makers better understand the impact of climate change on potato crop yield and to enhance sustainable water management in Egypt’s major crop-producing regions to alleviate water scarcity.

Practicing agricultural drainage strategies is necessary to manage excess water in poorly drained irrigated agricultural lands to protect them from induced waterlogging and salinity problems. This paper provides an overview of subsurface drainage strategies and the modeling of their performance using the DRAINMOD model. Given that the DRAINMOD model considers a fixed value of the surface depression capacity (SDC) for the whole simulation period, which does not suit many agricultural practices, the paper then assesses the model’s performance under time-variable SDC. It was revealed that adopting a fixed value of SDC for the whole simulation period in the DRAINMOD model causes it to produce improper predictions of the water balance in farmlands characterized by time-variable SDC. Such a model drawback will also adversely impact its predictions of the nitrogen and phosphorus fate in farmlands, which represent major inputs when managing both the agricultural process and agricultural water quality. Researchers should pay attention when applying the DRAINMOD model to farmlands characterized by time-variable SDC. Moreover, it is recommended that the DRAINMOD input module be improved by considering changes in SDC during the simulation period to ensure better management of the agricultural process and agricultural water.

Studies of real processes are based on measured data. In the past, the amount of available data was very limited. However, with modern technology, the information which is possible to obtain from measurements is more available, which considerably alters the possibility to understand and describe processes. Multivariate analysis is often used when large datasets which contains many variables are evaluated.

In this thesis, the multivariate analysis methods PCA (principal component analysis) and PLS (partial least squares projection to latent structures) has been applied to wastewater data collected at Hammarby Sjöstadsverk WWTP (wastewater treatment plant).

Wastewater treatment plants are required to monitor and control their systems in order to reduce their environmental impact. With improved knowledge of the processes involved, the impact can be significantly decreased without affecting the plant efficiency. Several variables are easy to measure directly in the water, while other require extensive laboratory analysis. Some of the parameters from the latter category are the contents of phosphorus and nitrogen in the water, both of which are important for the wastewater treatment results. The concentrations of these substances in the inlet water vary during the day and are difficult to monitor properly.

The purpose of this study was to investigate whether it is possible, from the more easily measured variables, to obtain information on those which require more extensive analysis. This was done by using multivariate analysis to create models attempting to explain the variation in these variables. The models are commonly referred to as soft sensors, since they don’t actually make use of any physical sensors to measure the relevant variable.

Data were collected during the period of March 11 to March 15, 2013 in the wastewater at different stages of the treatment process and a number of multivariate models were created. The result shows that it is possible to obtain information about the variables with PLS models based on easy-to-measure variables. The best created model was the one explaining the concentration of nitrogen in the inlet water.

The global move to more sustainable and renewable energy sources causes increased fluctuations in theelectric market. That fact combined with the Swedish regulations on micro producers make high levels ofself-use critical and have increased the interest in energy storage of energy from intermittent sources.Cooperation with Eksta AB have provided the opportunity to evaluate an innovative energy storage conceptfor a future exploitation area of around 17,2 hectares planned residential and urban area. This bachelorthesis studies the potential of using stormwater management ponds for small-scale energy storage in theform of pumped hydro energy storage (PHES). The focus is on storage of surplus energy from a solarenergy system designed for micro production and local energy supply. However, it also evaluates thepotential of using the equivalent dimensions for energy storage which storage level only change whenbuying or selling electricity at market prices for arbitrage purposes.Potential in the form of financial benefit and increased self-use of solar energy are studied through aquantitative methodology that, in the case of storing surplus energy from a solar system, use a simulationmodel developed for this thesis that takes Eksta´s contractual electric specifications into account. Toevaluate the case of energy storage for arbitrage a simulation model is used in the form of an algorithmbaseddrive strategy named “Optimal”, which has been recreated from research in the field of energy storageand drive strategies. The level of innovation is high on account of including such as energy additions to thestorage from rain water management, energy losses from dispersion of stored stormwater to surroundingground layers, it´s novel focus on a stormwater pond for energy storage, the rarely studied combination ofPHES and small scale solar systems and finally that the dimensions of the pump and turbine that is neededin PHES is based on PaT (pump as turbine) technology, allowing the reverse drive of a centrifugal pumpto operate as a turbine.Sensitivity analysis is included to increase the understanding of PHES-stormwater systems in the case of Eksta and as a concept for energy storage. The work also includes a brief examination of relevant regulationsin order to supply a wider perspective.The result shows that the implementation of a PHES-stormwater system during the years 2018 and 2019increased the self-use of generated solar energy by 28,59 % and provide the joint financial benefit of 5989SEK. The simulation model of energy storage for arbitrage during the years 2018 and 2019 resulted in thecombined financial benefit of 699 SEK when “Optimal” operation strategy is used and 678 SEK with apractically applicable operation strategy.The main conclusion is that PHES-stormwater systems as an energy storage for small-scale solar surplushas high potential to increase the self-use of solar energy but relatively low potential to increase the financialbenefits of small-scale solar systems. From the sensitivity analysis it can be concluded that the simulatedPHES-stormwater system is sensitive to small and medium ranged changes in storage capacity, efficiency,rate of dispersion, set electrical buying price and selectivity of which hours to empty the storage. This whilebeing generally insensitive to small and medium ranged variations in installed peak effect of the solar system,filling/emptying time and the relative size of the turbine compared to the pump.The conclusion from the simulation of arbitrage application is that the potential for financial benefit inthese circumstances is extremely low. The sensitivity analysis lead to the conclusion that the system issensitive to small and medium ranged variations in storage capacity, efficiency, filling/emptying time andmarginal operation costs.Besides the limited financial benefit, other potential hindrances may be the legality of connecting the systemelectrically, lack of financial benefits given to larger but still small-scale solar systems and the eventuality ofdisrupting the main function of the stormwater pond, which is purifying stormwater.

The water industry is moving from an end-of-pipe approach consistent with the linear economic model to a circular approach consistent with the circular economy model. The economic dimension of wastewater circularity has not received the attention that other dimensions have; this study attempts to fill this research gap by studying the economic dimension, in order to estimate the net opportunity cost of a non-circular water industry The financial and environmental benefits of treating wastewater, along with the associated operating and capital costs, are calculated to arrive at the opportunity cost and the 'closing the loop charge'. The analytical results reveal an estimated net opportunity cost of 643 million Jordanian dinar (JOD) (907 million US$) if the option not to go circular is chosen, with JOD 212 million (US$ 299 million) of this amount currently squandered. Furthermore, this indicates an average 'closing the loop charge' of JOD0.70/m(3) ($1.0/m(3)), which represents the average shadow price of the associated environmental externalities. Having thus shown a strong economic case for the circular model in the water industry, movements in all economic sectors to adhere to this model appear to be highly desirable.

The occurrence of radon (222Rn) in environment (groundwater and indoor air) from geogenic sources is receiving an growing attention due to its adverse impact on human health worldwide including Jordan. Highlighting the current status of radon in Jordan, the present study of radon concentrations in ground waters in the Amman-Zarqa basin (AZB) was investigated. Groundwater samples were collected from fifteen wells located in three main areas of Ras Al-Ain, Al-Rsaifeh and Al-Hashemite. Radon concentration was measure using Liquid scintillation counting (LSC) Tri- Carb 3110 with discriminator and the highest values for radon concentration in water were observed in Al-Rsaifeh area and ranged from 4.52 up to 30.70 Bq/l with an average of 11.22 Bq/l, which were attributed to the decay of naturally distributed uranium in phosphate rock from Al-Rsaifeh mines. In Ras Al-Ain area, the radon concentration were noted ranged from 0.6 to 5.55 Bq/l with an average of 2.82 Bq/l, and also in Al-Hashemite area were ranged from 0.77 to 5.37 Bq/l with an average of 4.04 Bq/l. The overall average concentration of tested samples was 5.77 Bq/l and found within the acceptable international levels. Ground water samples of Ras Al-Ain area showed good quality as was tested of low salinity. It recorded the lowest average radon concentration of 2.82 Bq/l. Also, Radon indoor and building materials was reviewed. In conclusion, this study presented an urged need for developing national regulations and standards as well as awareness program concerning the radon status in Jordan.Elsevier B.V.

Improving the accuracy of reference evapotranspiration (RET) estimation is essential for effective water resource management, irrigation planning, and climate change assessments in agricultural systems. The FAO-56 Penman-Monteith (PM-FAO56) model, a widely endorsed approach for RET estimation, often encounters limitations due to the lack of complete meteorological data. This study evaluates the performance of eight empirical models and four machine learning (ML) models, along with their hybrid counterparts, in estimating daily RET within the Gharb and Loukkos irrigated perimeters in Morocco. The ML models examined include Random Forest (RF), M5 Pruned (M5P), eXtreme Gradient Boosting (XGBoost), and Light Gradient Boosting Machine (LightGBM), with hybrid combinations of RF-M5P, RF-XGBoost, RF-LightGBM, and XGBoost-LightGBM. Six input combinations were created, utilizing Tmax, Tmin, RHmean, Rs, and U2, with the PM-FAO56 model serving as the benchmark. Model performance was assessed using four statistical indicators: Kling-Gupta efficiency index (KGE), coefficient of determination (R2), mean squared error (RMSE), and relative root squared error (RRSE). Results indicate that the Valiantzas 2013 (VAL2013b) model outperformed other empirical models across all stations, achieving high KGE and R2 values (0.95–0.97) and low RMSE (0.32–0.35 mm/day) and RRSE (8.14–10.30%). The XGBoost-LightGBM and RF-LightGBM hybrid models exhibited the highest accuracy (average RMSE of 0.015–0.097 mm/day), underscoring the potential of hybrid ML models for RET estimation in subhumid and semi-arid regions, thereby enhancing water resource management and irrigation scheduling.

During recent years a hybrid model has been set up for the operational forecasting of flood discharges in the 6750km ² Tyrolean part of the River Inn catchment in Austria. The catchment can be characterized as a typical alpine area with large variations in altitude. The paper is focused on the error analysis of discharge forecasts of four main tributary catchments simulated with hydrological water balance models. The selected catchments cover an area of 2230km ², where the non-glaciated and glaciated parts are modeled using the semi-distributed HQsim and the distributed model SES, respectively.The forecast errors are evaluated as a function of forecast lead time and forecasted discharge magnitude using 14 events from 2007 to 2010. The observed and forecasted precipitation inputs were obtained under operational conditions. The mean relative bias of the forecasted discharges revealed to be constant with regard to the forecast lead time, varying between 0.2 and 0.25 for the different catchments. The errors as a function of the forecasted discharge magnitude showed large errors at lower values of the forecast hydrographs, where errors decreased significantly at larger discharges being relevant in flood forecasting

Iraq depends on its water resources from the water of the Tigris and Euphrates Rivers and their tributaries. Now, the flow of these rivers is decreasing, and Iraq is experiencing a water shortage problem. The situation is expected to be graver in the future if no action is considered. It is expected that the population will be about 70 million in 2050 and about 90 million in 2070. In such a case, thus, the quantities of water available in the future will not besufficient to produce most of the requirements of food security, whether that be from agricultural or animal products. To overcome this problem, water management planning should be based on scientific background to overcome the present and expected problems. One of the main factors to be considered should be based on scientific studies of the virtual water footprint of different food crops to provide the largest possible amount of virtual water and avoid the acute shortage of its national water from surface and ground irrigation water (blue water) and rainwater (green water), in addition to working hard to provide the largest possible amount of desalinated water and refined sewage (gray water). In addition, any strategic plan for sustainable development in the country must be comprehensive so that it is not satisfied with improving the situation in the field of food security related to water security, but rather among its other elements is community development that directly affects food security, including setting policies to reduce consumption by reducing the steady increase in population where the population rate is 2.97% now. Collective awareness and guidance programs in all the fields of water and food security are very important to be adopted, so that everyone knows that the issue of food security and what derives from it are an existential issue related to the survival of Iraq as a state and people. In this research, facts are stated so that action is to be considered to minimize the water shortage problem. The new strategic water resources management plan is to be adopted that considers existing and future expected problems.

The Hydraulic Institute has completed the task of developing a new ANSI/HI standard 12.1-12.6 (2005) for rotodynamic (centrifugal) slurry pumps covering nomenclature, definitions, applications, and operation. The standard provides examples of the different slurry pump types and contains an extensive section on pump and slurry definitions. The effect of slurry on pump performance is covered along with the pumping of froth. Reference is also made to ANSI/HI standard 9.6.7 (2004), which contains a new method for pump performance correction when handling viscous fluids. Classification of slurry services is established and then is used to determine limitations on velocities and total head per pump in order to obtain acceptable wear performance. The new service class, head per stage and other limits are directly related to capital and other cost considerations that will affect solids transport system economics. The writers review the contents of the new standard, highlight the main points, and discuss the reason for the slurry classification, corresponding limits and expected implications, particularly with respect to operating costs of the pumps in solids transport systems

There is a wide variety of industrial pastes or non-settling slurries pumped in mining, dredging and reclamation projects as products, refuse and tails. The types and/or names of some of the common ones are alumina red mud, phosphate clays, tar sands mature fine tails, tar sands (CT) consolidated clays and fly ash. The pipeline performance or friction of these varies dramatically with the type, its concentration and the particulars of the actual slurry making it difficult to select pumping equipment and to design associated pipelines. The GIW Hydraulic Laboratory in Grovetown Georgia has tested a number of these slurries over the last 30 years for various mining customers. Where available in the public domain and/or where permission has been obtained, the results of those tests are presented in this paper in a form usable for pipeline and pump system designers and users.

The Hydraulic Institute has completed the task of developing a new ANSI/HI standard 12.1-12.6 (2005) for Rotodynamic (Centrifugal) Slurry Pumps covering nomenclature, definitions, applications, and operation. The standard provides examples of the different slurry pump types and contains an extensive section on pump and slurry definitions. The effect of slurry on pump performance is covered along with the pumping of froth. Reference is also made to ANSI/HI standard 9.6.7 (2004), which contains a new method for pump performance correction when handling viscous fluids.Classification of slurry services is established and then is used to determine limitations on velocities and total head per pump in order to obtain acceptable wear performance. The new service class, head per stage and other limits are directly related to capital and other cost considerations that will affect solids transport system economics. The writers review the contents of the new standard, highlight the main points, and discuss the reason for the slurry classification, corresponding limits and expected implications, particularly with respect to operating costs of the pumps in solids transport systems.

The Hydraulic Institute has just completed the task of developing a new ANSI/HI standard on Rotodynamic (Centrifugal) Slurry Pumps covering nomenclature, definitions, applications, and operation. The standard provides examples of all the different types of pumps available and has an extensive section on definitions. Slurries and their effect on performance and wear are covered. A slurry service class is established which then is used to limit velocities and head produced per pump to give acceptable wear. A special section deals with mechanical seals and a new method for determining flange loads is presented and guidelines are given for commissioning, start-up etc.The head limits and the performance derating are of special interest when centrifugal slurry pumps are applied to thickened tailings and paste-like slurries. For Newtonian liquids, the Hydraulic Institute's Viscosity Correction Method (ANSI/HI 2004) provides a procedure widely used for viscous effects on the performance. For the homogeneous flow of viscous slurries, the new slurry standard refers to an applicable viscosity to use with the method and to "consult the pump manufacturer for guidance regarding non-Newtonian slurry pump performance."Experimental performance results are presented here and applied to the viscosity correction method for a simulated tailings product slurry characterized by a fully sheared yield stress of about 100 Pa, evaluated from pipeline data. The pump was a GIW-LCC type three-vane all metal unit with a 0.3m-diameter impeller having an open shroud with a simple auger-like inducer. Results are also given for an underground hydraulic fill product characterized by a Newtonian kinematic viscosity which is 1300 times that for water. The different results obtained here point out the strong influence the rheological behavior has on the choice of pump size and the power requirement.

Cyclone feed centrifugal slurry pumps in semi-autogenous grinding (SAG) mill and other cyclone feed circuits see coarse size slurries at high concentrations that can result in high wear if the pump is not designed, selected, sized and operated correctly. The high proportion of static head of the normal cyclone feed circuits usually results in a relatively flat system curve which in conjunction with the typically flat slurry pump curve results in large changes in operating flow with small changes in system head. When this is combined with the normal (or abnormal) fluctuations in the output from the mill upstream of the pumps, any shortcomings in the pump control system and/or matching of the pump means large fluctuations in flow and increased wear. This difficulty could be corrected by continuous variations in speed. A means of control by which the speed is changed in an appropriate way is suggested here. In this case then the pump-input power, the known water performance of the pump and the system flow, can be used to calculate an effective pump discharge pressure. By comparison with a calculated system head, the pump speed can be regulated such that the pressures are equal and the system stable for any practical variation of incoming flow or specific gravity.

Blue green infrastructure (BGI), in recent decades, have been increasingly recognized as robust stormwater control measures to reduce urbanflooding, promote infiltration, and restore a catchment’s flow to its pre-development stage. However, studies comparing the hydrologicalbenefits of BGI alternatives at catchment scale are often limited to single catchment or single/few BGI options scaled over a catchment.This study designed a set of BGI alternatives as a combination of different BGI facilities in terms of the following: (a) spatial distributionscale (end-of-pipe vs. decentralized) and (b) naturalness scale (less engineered vs. more engineered), in three different urban catchmentsrepresenting an inner city, a residential suburb, and a new urban housing. In addition, their hydrological performances were compared.A 10-year return period design rain and a continuous rain series of 11 years were modelled for each BGI alternative using the computermodel stormwater management model (SWMM). It was observed that in most catchments, decentralized alternatives (both engineeredand natural) showed better potential to reduce the magnitude and frequency of flooding than centralized measures. Similarly, the testeddecentralized natural, less engineered alternatives showed higher potential to increase infiltration than the decentralized engineered alternativesin all three catchments. Meanwhile, infiltration-based BGI alternatives showed similar potential to mimic pre-development flow as otherdecentralized BGI alternatives.

As of January 1st, 2024, all municipalities must have a water service plan. A water service plan must contain each municipality's long-term plan to provide public water services in the future and solutions that need to be taken in the event of a cloudburst to protect water and sewage facilities. The change in law was introduced on January 1st, 2023, which has given municipalities a tight timetable to develop this plan.

The study has investigated what the water service plan in Västerås municipality needs to contain in order to fulfill the requirement for solutions in the event of cloudbursts, identify points in the waste and stormwater network that are potentially vulnerable to cloudbursts, and provide suggestions for torrential rain measures. In order to fulfill the purpose, a risk and vulnerability analysis has been carried out to identify points in the waste and stormwater network that are potentially vulnerable to cloudbursts. The analysis included a workshop, with key individuals at Mälarenergi Vatten AB, and a risk matrix that was used as an assessment basis. From the risk matrix, points that were potentially vulnerable to cloudbursts were identified and a low-point mapping was performed in SCALGO Live at the selected points. The rain events performed in the mapping were 10-, 20- and 100-year rainfalls. The low-point mapping was compared with a cloudburst mapping with land runoff and conduit network, which is a mapping with a high degree of detail, to investigate whether low-point mapping can be a suitable basis for a water service plan.

The result of the risk and vulnerability analysis was that seven points, which were given as suggestions during the workshop, had high-risk values and were potentially vulnerable to cloudbursts. Three out of the seven points were selected for further analysis: Branthovda, Skiljebo, and Önsta-Gryta, all of them located in Västerås city. All of these sensitive points were in the stormwater network. The low-point mapping in SCALGO Live performed over these three points showed major flooding during a 100-year rainfall event. The proposed cloudburst solutions for the sites were storage areas and cloudburst roads. When comparing low-point mapping and cloudburst mapping with ground runoff and conduit networks, the cloudburst mapping showed a minor flood for Branthovda and Skiljebo. In Önsta-Gryta, the difference between the mappings was minimal. This was due to the results of the cloudburst mapping showing that the stormwater pipes in the area were overloaded even with a 10-year rain, which was similar to the condition in the low-point mapping that the stormwater pipes are assumed to be filled. With this, only a low point mapping can show an area's potential for being vulnerable to cloudbursts but does not say anything about how the waste or stormwater network is affected. However, low point mapping can help identify areas in built-up areas that could be vulnerable to flooding.

Denna studie genomfördes på uppdrag av det statliga forskningsinstitutet Formas. Syftet med rapporten var att undersöka hur effektiva våtmarker är som tilläggsrening av avloppsvatten, detta med avseende på reducering av läkemedel samt skadeeffekter på akvatiska organismer. Rapporten baserades på en tidigare studie utförd av Breitholtz et al. (2012) där mätningar av läkemedelshalter samt mortalitet och larvutveckling hos hoppkräftor, Nitocra spinipes, gjordes i fyra olika våtmarker.  De fyra våtmarkerna ligger i Eskilstuna, Oxelösund, Nynäshamn och Trosa. Deras mätningar undersökte mortalitet och larvutvecklingskvot för hoppkräftor i prover utspädda med bräckt vatten vid koncentration avloppsvatten på, 11,25 %; 22,5 %; 45% och 90 %. Proverna för läkemedelshalter späddes inte ut och enbart ett mätvärde per våtmark togs vid inflödet och utflödet.

I denna rapport undersöktes dessa frågeställningar: (1) Är anlagda våtmarker som tilläggsrening en effektiv metod med avseende på skadeeffekter hos hoppkräftor, (2) till vilken grad reduceras halten läkemedel när våtmarker används som tilläggsrening samt (3) finns det ett samband mellan läkemedelsrester och hoppkräftornas överlevnad?

För att besvara de tre frågeställningarna genomfördes en metaanalys av data från studien av Breitholtz et al. (2012). Hoppkräftors mortalitet, larvutvecklingskvot (LDR) och koncentration av läkemedel analyserades. Endast mortalitet och larvutvecklingskvot hade tillräckligt med data för utförande av en metaanalys. Läkemedelsanalysen kunde bara göras på en grundläggande nivå.

Metaanalysen programmerades i MATLAB R2019b, där skillnaden i medelvärdet för mortalitet respektive larvutvecklingskvot beräknades mellan in- och utflöde för de fyra våtmarkerna. Skillnaderna för varje våtmark vägdes samman med invers-varians metoden för att få ett sammanvägt medelvärde. Analysen av läkemedel gjordes på nio läkemedel från Breitholtz et al. (2012). De nio valdes ut då de har pekats ut av Svenska Miljöinstitutet som intressanta ur ett avloppsreningsperspektiv. Excel användes för att göra enklare statistiska analyser mellan in- och utflöde i våtmarkerna. Slutligen gjordes en jämförelse mellan hoppkräftors skadeeffekter och läkemedelshalter genom att ta ut skillnaden i medelvärde mellan in- och utflöde.

Resultatet från analyserna visade att när våtmarker användes som tilläggsrening minskade mortaliteten hos hoppkräftor för koncentrationerna 11,25 % och 90 % avloppsvatten. För koncentrationerna 22,5 % och 45 % fanns däremot ingen signifikant skillnad i mortalitet. Larvutvecklingskvoten minskade efter våtmarksbehandlingen för alla koncentrationer utom 90 %. Läkemedelshalten minskade i snitt med 30 % mellan inflöde och utflöde i våtmarkerna. För läkemedlen sulfametoxazol och oxazepam kunde dock en ökning ses efter behandling med våtmark. Ingen direkt trend kunde utläsas mellan läkemedelshalt och mortalitet hos hoppkräftor. Detta berodde troligtvis på att andra faktorer och föroreningar påverkade hoppkräftornas mortalitet och larvutvecklingskvot i högre grad än läkemedelshalterna.

I studien kunde ingen slutsats dras om huruvida tilläggsvåtmarker är en effektiv reningsmetod med avseende på skadeeffekter hos hoppkräftor. Hoppkräftor är bra indikatorer på föroreningar i vattnet, dock är det svårt att bestämma vilka föroreningar som påverkar mest i detta fall. Detta medför att inga direkta samband mellan läkemedel och hoppkräftors mortalitet kunde påvisas i studien. De undersökta läkemedlen reducerades generellt. Eftersom mätningarna gjordes under vinterförhållanden då nedbrytningen i våtmarken är som minst effektiv bör resultatet ses som ett lägsta värde.

The steady supply of fresh water is, and has always been, one of the most important functions in human societies. Different users have been able to take advantage of this resource in different extents and for different purposes. The major areas for water usage are drinking water, water supply for industrial purposes and the usage in agricultural sector.

By dimensioning the supply- and sewer systems accordingly to the demand of the users a more sustainable and optimal system can be achieved. A proper dimensioning has six general factors it should to take in consideration. These are the size of the population, water consumption in residents, general water consumption in schools and offices, water consumption in industry, leakage and different water losses. With a background of these factors this reports main focus and purpose is analysing the variation in water consumption for different consumers (such as residential houses or apartment blocks) in different time intervals (in this report during days and years) and in respect to different factors. The factors that has been chosen to be examined is how water consumption depends on mean age of the consumers and the outdoor temperature. To complete this study water consumption data of different areas in Borås has been provided from the Swedish consultant firm Tyréns. Before analysing the data another study was made by Victor Eliasson, which included the revealing of different faults in the provided data. As a result of this study the most reliable data was chosen to further analysis with respect to the chosen aspects. During the project the calculation- and modelling program Matlab was used alongside the chart program excel. These two programs combined made it possible to handle large amounts of data and present it in different graphs and models. Conclusions could later be made by analyses and different statistical methods. The result from the comparison between areas with different mean ages of the residents showed that the area with high mean age (80 years) hade a higher water consumption than the other areas. The variation in water consumption differed as well between the area with the high mean age compared to the other areas. A regression- and correlation analysis between water consumption and temperature was performed to see if water consumption is depending on the outdoor temperature. The function of a regression analysis is to describe the relation between different parameters with a mathematic model (in this study a linear model). A correlation analysis is then performed to tell how well the mathematic model describes the relation. A conclusion could be made that the water consumption tends to increase with increasing temperature during parts of the year, since a correlation could be found during mars to September. The strongest correlation was in general during May and July for all the areas. No conclusion of how the variation i water consumption depends on different consumers could be made for the analysis during a day and a year. In contrast to the parameters that had a correlation with water consumption there was no visible connection between water consumption over a year or day depending on different users. 

Operational forecasts of snow melt runoff in Sweden are currently running with precipitation and temperature as the main input variables and calibrated with runoff data, and there is an interest to make better use of new measurement systems for distributed snow data. At the same time, various data assimilation techniques are becoming more frequently used in hydrological modeling, in order to reduce uncertainties related to both model structure errors and errors in input and calibration data. Thus, it is important to address not only what type of snow data that can be used to improve the model predictions, but also what type of input data and model structures that are optimal in relation to the available snow data. The objective of this study is to investigate to what extent the runoff predictions can be improved by assimilation of temporal and spatially distributed snow data, and if the improvements depend on the choice of model structures, for instance the use of energy balance or day-degree snow models. In order to achieve these objectives a new distributed snow model has been implemented into the hydrological modeling framework HYSS/HYPE. This model can easily be setup with either an energy balance model or a day-degree model for the snow pack calculations, and it is easy to run the model with different spatial resolutions. In the fully distributed case, snow drift processes are implicitly included in the model through a precipitation distribution model, based on topographical information and wind direction. The model was applied to a mountain basin in northern Sweden used for hydropower production, where extensive snow measurements were taken during the last two winters 2007-2009. A climate station is located at the outlet of the regulation lake, including automated point measurements of snow depth, snow mass (snow pillow), snow wetness and snow temperature. Distributed snow cover data was sampled using ground-penetrating radar from snow mobiles. Measurements were taken at the time of the maximum snow cover, providing a data set with snow depth, snow density, snow water equivalent along 20 km long transects in representative areas of the basin. The precipitation distribution model was calibrated using the distributed SWE data from the GPR measurements. Application of the calibrated model to previous years without available snow data show that the runoff predictions was improved compared to calibrations without the distributed snow data, however the improvements were larger for the energy balance compared to the day-degree model. Further developments will include assimilation of the temporal and spatial snow data to adjust the distribution of various input variables, for instance air temperature and wind speed.

According to The Swedish Water and Wastewater Association (SWWA), a storm waternetwork must be able to handle a rainfall with a return period of 10 years. In order toevaluate whether a drain system is adequately dimensioned, a storm water model can beestablished. This requires knowledge about the levels at which the conduits are situated,and this information is insufficient in many areas. However, the pipes could largely beassumed to follow the topography and the pipes levels can be estimated from it.Therefore, the aim of this study was to develop a method for how the level of stormwater conduits could be assessed from the ground level, and the significance thismethod had for storm water modeling. A further aim was also to, according to thismethod; assess the storm water systems of the Lidingö community, which lackedinformation on the pipe levels. Furthermore, for the method to be useful it wasimportant to make it easily applicable even to large storm water networks.The method was developed using parts of the storm water network in Sundbyberg,Stockholm. The levels of the conduits were known beforehand, and an analysis of themresulted in a method where the depth of the manhole, which controls the levels of theconduits, was estimated to 2 m. An exception had to be made when the conduits were inreverse slope, in which cases horizontal slope was assumed.When evaluating the impact from the depth assessment on the runoff, the uncertaintyfrom the imperviousness was taken into account by using three different scenarios;unchanged, 30% lower and 30% higher imperviousness. The risk of flooding for eachone of the manholes was weighted from the results of these three scenarios. Thisresulted in a pressure level for each manhole, either above ground, below ground orinconclusive. This was done for the model with both known levels for the conduits, andwith the assessed levels. In order to evaluate how well the method for applying thedepth worked, the status of each manhole was compared between the two models.The conclusion from this study was that the method developed here, more or less gavethe same results as when the levels of the conduits were previously known.Discrepancies arose mainly in ditches, but also for a few landlocked areas and outlets.For the Lidingö storm water network, 18 % of the wells ended up with a pressure levelabove ground when applied to a rain with a 10 year return period. Another 16 % of thewells were inconclusive.

Swimming pools are used as leisure centers, for sports or as therapeutic rehabilitation, and in Stockholm municipality there are 15 municipal swimming facilities and very many private ones in the form of, for example, hotel pools. A relatively inattentive problem with these pools lies in the chemical reactions that take place in the water. Sodium Hypochlorite reacts in the pool with organic material to form Adsorbable Organic Halides (AOX) and Extractable Organic Halides (EOX). These get stuck in the filter at the plant locally and free chlorine can form additional AOX in the wastewater network. These compounds are harmful for humans and animals to ingest and sometimes even to come into direct contact with. These substances have been studied to bioaccumulate in living organisms and have caused problems such as impaired reproductive capacity and other cell damage. The substances have also been observed to accumulate in dunes in watercourses. These substances that are created then get stuck in the filtration systems that are located locally at the plants due to pressure differences in these. When this happens, the filters need to be backwashed and this generates concentrated contaminated water. 

In the background, I have examined different kinds of disinfection methods in swimming pools, as well as different ways to treat wastewater of AOX and EOX in treatment plants. This was done to build a good background to the issue at hand of AOX and EOX. 

In this bachelor's thesis, I have studied how many swimming facilities there are in the catchment area of the Käppalaverket, Bromma treatment plant, and Henriksdal treatment plant. With this information, I have found out how much water is generated by pools at these facilities and supplemented these figures using standard values obtained from managers and estimated from received values. 

The effectiveness of automated treatment processes within wastewater treatment plants ultimately depend on the quality of the measurement data that is given from the installed sensors. Sensor faults affect the control of the treatment plants and are often the reason different control strategies fail. Today there is a lack of standardized guidelines for how to organize and work with online sensors at Swedish wastewater treatment plants which limits the opportunities for treatment plants to reach their effluent criteria in a resource efficient manner. Much research has been done on ways to optimize control strategies but the role of sensors in the efficiency of the treatment plants has not been given the same level of attention. The purpose of this thesis has been to examine how instrumentation at wastewater treatment plants can be organized and structured to ensure good quality measurement data and to examine how sensor faults affect the treatment process.

Within the thesis a literature study was conducted where instrumentation at wastewater treatment plants was examined. The effects of sensor faults were examined by simulating a pre-denitrification process in Benchmark Simulation Model no. 2 where off-sets (biases) and drift where added to measurements from different implemented sensors. The simulations showed that positive off-sets (0.10–0.50 mg/l) in an ammonium sensor within a cascaded feedback-loop adds to the energy consumption used for aeration by roughly 4-25%. It could further be shown that all types of faults in a DO sensor in the last aerated basin had significantly larger effect on the treatment process than the same fault in any of the other DO sensors in the preceding basins. If the last aerated basin is designed to have low DO concentrations the DO sensor in that basin is the most important DO sensor to maintain. Positive off-sets (200–1 000 mg TSS/l) in suspended solids sensors used for control of waste activated sludge flow contributed to large increases of ammonia, by 29-464%, in effluent waters. Negative drift in DO sensors showed that significant savings in aeration energy, roughly 4%, was possible to achieve with more frequent maintenance.

Whether a sensor is affected by a positive or a negative fault, be it off-set or drift, will affect how much and in what way the treatment process will be affected. The study of sensor faults showed that the effect of a positive or a negative fault varied and that the effect on the treatment process was not linear. The effect of a sensor fault on the treatment process will ultimately depend on the implemented control strategy, settings in the controllers and on the controlled process.

Arsenic in the groundwater of Bangladesh is a serious natural calamity and a public health hazard. Most groundwater from the shallow alluvial aquifers (<150 m), particularly in the Holocene plain lands, are vulnerable to As-enrichment. Delta plains and flood plains of the Ganges-Brahmaputra river system are moderately to severely enriched and more than 60% of the tube wells are affected. Shallow aquifers in the Meghna river basin and coastal plains are extremely enriched with more than 80% of the tube wells affected. Aquifers in the Pleistocene uplands and Tertiary hills are low in As. The vertical lithofacies sequence of the sediments from highly enriched areas of the country show two distinct lithofacies associations-a dominantly sandy channel-fill association and a fine-grained over bank association. The sediments can be grouped into 4 distinct lithofacies, viz. clay, silty clay, silty sand and sand. Thin section petrography of the As-enriched aquifer sands shows that the sands are of quartzolithic type and derived from the collision suture and fold thrust belt of the recycled orogen provenance. Groundwater is characterized by circum-neutral pH with a moderate to strong reducing nature. The waters are generally of Ca-Mg-HCO3 or Ca-Na-HCO3 type, with HCO3- as the principal anion. Low SO42- and NO3-, and high dissolved organic C (DOC) and NH4+ concentrations are typical chemical characteristics of groundwater. The presence of dissolved sulfides in these groundwaters indicates reduction Of SO4. Total As concentration in the analyzed wells vary between 2.5 and 846 mug l(-1) with a dominance of As(III) species (67-99%). Arsenic(III) concentrations were fairly consistent with the DOC and NH4+ contents. The HNO3 extractable concentrations of As (As-NO3) in the sediments (0.5-17.7 mg kg(-1)), indicate a significant positive correlation with Fe-NO3, Mn-NO3, Al-NO3 and P-NO3. The concentrations Of S-NO3 (816-1306 mg kg(-1)) peaked in the clay sediments with high organic matter (up to 4.5 wt.%). Amounts of oxalate extractable As (As..) and Fe (Fe x) ranged between 0.1-8.6 mg kg(-1) and 0.4-5.9 g kg(-1), respectively. Arsenic(ox) was positively correlated with Fe-ox, Mn-ox, and Al-ox in these sediments. Insignificant amounts of opaque minerals (including pyrite/arsenopyrite) and the presence of high As contents in finer sediments suggests that some As is incorporated in the authigenically precipitated sulfides in the reducing sediments. Moreover, the chemical extractions suggest the presence of siderite and vivianite as solid phases, which may control the aqueous chemistry of Fe and PO43-. Reductive dissolution of Fe oxyhydroxide present as coatings on sand grains as well as altered mica (biotite) is envisaged as the main mechanism for the release of As into groundwater in the sandy aquifer sediments.

Introduction: Many cities in Sweden have many low points in their terrain and areaffected by heavy rain. Urban sprawl often exacerbates the problem by increasing theamount of paved surfaces while reducing available land for stormwater treatment. Thismeans that stormwater flows that need to be managed can be very heavy and drainquickly. It is therefore important that cities achieve long-term sustainable stormwatermanagement that can cope with current and future climate change. This report willexamine how Karlstad and Växjö municipalities are working and planning for theincreased risk of stormwater and study the different solutions currently in use.

Method: This report began with a literature study to deepen knowledge and get a goodbase. In order to answer the research questions, two case studies and three interviewswere conducted with respondents from the Water and Wastewater Departments ofVäxjö and Karlstad Municipality. One expert was also interview. Document analysiswas then carried out based on the plan description, sustainability index and thestormwater study in order to obtain as comprehensive material as possible.

Results: The planning and work started with the preparation of a flood mapping and afirst impact assessment. No full action plan has been prepared by the consultedmunicipalities. In order to start the work, Karlstad will employ a rainfall coordinator.Most common solutions used in municipalities are treatment ponds, levellingreservoirs, street management and renewal of the sewerage and stormwater system. Aspecial solution in Växjö is the reduction of stormwater tax. Location, knowledge, laws,time and the cooperation of the water department with property owners and otherdepartments in the municipality are important elements that influence theimplementation of different solutions.

Analysis: From the results it can be concluded that the municipalities are working andplanning well with the increased risk of rainfall in low-lying areas. However, morework can be done by producing an action plan adapted to these areas. The solutionapplied depends on a number of factors. These factors are adding safety factors tostormwater facilities and increasing the capacity of the pipeline system. The work iscontinued through good cooperation the different technical facilities in themunicipalities but also property owners as it often leads to a good and carefullyprepared solution. The municipalities explain that using cost-effective solutions isimportant because the funding comes from the water and wastewater departments tax.It is speculated that a change in the law allowing the water and wastewater departmentto receive funding for stormwater measures would have minimized flood risks.

Discussion: The results are considered useful because the municipalities can learn fromeach other's planning and work as well as help each other in developing sustainablestormwater solutions. The result promotes a better understanding of the factorsunderlying the chosen solutions. The generalization of the results can be questioned asit is site-specific. However, it can be applied because it increases understanding of howto address a similar problem in another location or municipality. 

Pollution of a watershed by different land uses and agricultural practices is becoming a major challenging factor that results in deterioration of water quality affecting human health and ecosystems. Sustainable use of available water resources warrants reduction of Non-Point Source (NPS) pollutants from receiving water bodies through best management practices (BMPs). A hydrologic model such as the Soil and Water Assessment Tool (SWAT) can be used for analyzing the impacts of various BMPs and implementing of different management plans for water quality improvement, which will help decision makers to determine the best combination of BMPs to maximize benefits. The objective of this study is to assess the potential reductions of sediments and nutrient loads by utilizing different BMPs on the Yarra River watershed using the SWAT model. The watershed is subdivided into 51 sub-watersheds where seven different BMPs were implemented. A SWAT model was developed and calibrated against a baseline period of 1998–2008. For calibration and validation of the model simulations for both the monthly and annual nutrients and sediments were assessed by using the Nash–Sutcliffe efficiency (NSE) statistical index. The values of the NSE were found more than 0.50 which indicates satisfactory model predictions. By utilizing different BMPs, the highest pollution reduction with minimal costs can be done by 32% targeted mixed-crop area. Furthermore, the combined effect of five BMPs imparts most sediments and nutrient reductions in the watershed. Overall, the selection of a BMP or combinations of BMPs should be set based on the goals set in a BMP application project. 

Treatment of waste water containing high amount of anthropogenic nutrient is a matter of great necessity acknowledged extensively.  Phosphorus (P) is one of the major nutrients of waste water threatening the aquatic ecosystems. If the phosphorus amount exceeds the system limits, growth of algae and microorganisms in system starts to speed up and consumption of oxygen is hence increased. Because of depletion of oxygen by algae the system is transformed from oxygen based (aerobic) to non-oxygen based (anaerobic) system threatening the ecosystem. 

The increasing removal actions of phosphorus existing in wastewater by treatment around the world contributes to preserve the natural ecosystem to a better situation. In this study a literature survey was carried out and different methods of phosphorus treatment were investigated such as wetlands filter wells, infiltration beds and filter materials. Then two mineral based filter materials, Polonite® and Sorbulite® were evaluated experimentally in laboratory conditions.  

In this study hydraulic conductivity and phosphorus sorption capacity of two mineral-based filter materials were analyzed and evaluated. The objective was to investigate the hydraulic conductivity and sorption capacity of the materials. Different particle sizes were also tested aiming to find the optimum particle size of the filter materials.  

The analysis was done by testing the filter materials in laboratory experiments. Two sets of hydraulic conductivity and sorption batch experiments were done for five different particle sizes, according to universal sieve numbers categories of the particle sizes: (0.25-1 mm) (1-2 mm) (2-4 mm) (4-5.6 mm) (5.6-8 mm). The adsorption mechanism was explained briefly, and the two mineral-based materials are expressed and clarified. Finally, the experiment tests to measure the hydraulic conductivity and sorption capacity were explained. The experimental work was conducted for eight different phosphate concentrations (PO4-P) and various particle sizes of Polonite and Sorbulite. The hydraulic conductivity and sorption capacity in batch experiments were measured for periods of 24 and 48 hours, respectively. 

The results showed that both filter materials have high and acceptable hydraulic conductivity specifically at large particle sizes. For the adsorption capability it was observed that both materials can adsorb almost all the phosphorus in the solution. Consequently, no major distinction was seen between Polonite and Sorbulite; eventually it is concluded that the current sizes of particles are too much for such range of concentration. The solution for future studies is to carry out the sorption batch experiment for either smaller particle sizes or for higher concentration of phosphate solution.  

Water management in residential areas often faces challenges such as unpredictable shortages and damaging overflows due to inadequate monitoring of tank water levels. This study presents the design and implementation of an Internet of Things (IoT)-based tank water monitoring system aimed at providing a reliable and efficient solution to these issues. Utilizing advanced sensor technology, the system accurately monitors water levels, volume, and quality within storage tanks. It incorporates dual sensors that enhance reliability: one sensor manages the water level, initiating pump activation when levels fall below a critical threshold, while the second sensor prevents overflows by deactivating the pump once the water level reaches a pre-set maximum. The system is designed to be user-friendly, offering real-time water level data and control via an Android application or web dashboard. This allows for remote operation of the motor pump, ensuring that water availability is consistent and secure, while also safeguarding against overflows and subsequent water wastage. The implementation of this IoT system demonstrates significant potential for enhancing water resource management in residential settings, promoting both sustainability and ease of use.

It is important to determine the limits of flow regimes in the design of stepped weirs because of the hydraulic performance of each regime. The present study investigates the effect of downstream slope and rock fill materials on flow regimes in gabion stepped weirs. Nine physical models of gabion weirs were used in the experiments. The models’ downstream slopes ranged from 1:05 to 1:4 V:H. In addition, two types of rockfill materials: crushed stone of 0.42 porosity and rounded gravel of 0.38 porosity were used to study the effect of rockfill materials on flow regimes. The nominal size of the crushed stone was (37.5 mm - 13.2 mm) D50 = 23 mm and the nominal size of the rounded gravel was (26.5 mm - 13.2 mm) D50 = 16 mm. Each model has been tested with ten runs for discharge per unit width ranging (from 0.006 to 0.105 m3/sec. m) to cover all flow conditions and flow regimes. The onset of each flow regime for all physical models has been observed. The experimental data of the gabion stepped weirs have been used to develop equations to estimate the onset of each flow regime. The coefficient of correlation (R) of the developed equations ranged between 0.95 to 0.97. The results indicated on the steeper downstream slope models (1:0.5, 1:0.83), there is interference between the nappe and transition flow regimes. The nappe flow regime has not appeared on all steps at the same time. Moreover, the shape and size of the rockfill materials have an insignificant effect on flow regimes, especially at a high flow rate.

With an ever-increasing human population, access to clean water for human use is a growing concern across the world. Seawater desalination to produce usable water is essential to meet future clean water demand. Desalination processes, such as reverse osmosis and multi-stage flash have been implemented worldwide. Reverse osmosis is the most effective technology, which uses a semipermeable membrane to produce clean water under an applied pressure. However, membrane biofouling is the main issue faced by such plants, which requires continuous cleaning or regular replacement of the membranes. Chlorination is the most commonly used disinfection process to pretreat the water to reduce biofouling. Although chlorination is widely used, it has several disadvantages, such as formation of disinfection by-products and being ineffective against some types of microbes. This review aims to discuss the adverse effect of chlorination on reverse osmosis membranes and to identify other possible alternatives of chlorination to reduce biofouling of the membranes. Reverse osmosis membrane degradation and mitigation of chlorines effects, along with newly emerging disinfection technologies, are discussed, providing insight to both academic institutions and industries for the design of improved reverse osmosis systems. 

Rivers Euphrates and Tigris are in southwest Asia. The main utilizers of the water of these rivers and tributaries are Turkey, Syria, Iran and Iraq. These rivers rise in Turkey, which makes it the riparian hegemon. Some of the tributaries of the Tigris and Shat Al-Arab Rivers rise in Iran, which makes it the riparian hegemon for these rivers. The lower countries in the catchments are Iraq and Syria and for this reason, they always to ensure the quantity of water required to satisfy their requirements. All these countries are in the Middle East (ME), which characterized by its shortage of water resources. Since the 1970s conflict between riparian counties were noticed due to shortage of available water required, high population growth rate and food security, energy requirements, economic and technological developments and political fragmentation. In addition, there is no public awareness program in all riparian countries and the water management practices are so old leading to high rate of losses. This caused tensions, which sometimes escalated to the verge of war. A mediator is required that is capable to bring all countries concerned to the negotiation table. Syria and Iraq are to give Turkey and Iran some incentives to cooperate. Furthermore, strategic plan based on comprehensive resources development to ensure good water management, minimum water loses, and waste must be adopted by the countries within the basins. This due to the fact that modeling studies of the future suggest that water shortage problem will intensify.

Modelling drought is vital to water resources management, particularly in arid areas, to reduce its effects. Drought severity and frequency are significantly influenced by climate change. In this study, a novel hybrid methodology was built, data preprocessing and artificial neural network (ANN) combined with the constriction coefficient-based particle swarm optimisation and chaotic gravitational search algorithm (CPSOCGSA), to forecast standard precipitation index (SPI) based on climatic factors. Additionally, the marine predators algorithm (MPA) and the slime mould algorithm (SMA) were used to validate the performance of the CPSOCGSA algorithm. Climatic factors data from 1990 to 2020 were employed to create and evaluate the SPI 1, SPI 3, and SPI 6 models for Al-Kut City, Iraq. The results indicated that data preprocessing methods improve data quality and find the best predictors scenario. The performance of CPSOCGSA-ANN is better than MPA-ANN and SMA-ANN algorithms based on various statistical criteria (i.e., R², MAE, and RMSE). The proposed methodology yield R² = 0.93, 0.93, and 0.88 for SPI 1, SPI 3, and SPI 6, respectively.

Ett behov finns av att fördröja dagvatten innan det släpps på det kommunala ledningsnätet för att minska flödestopparna och undvika överbelastning. Studien avser att ta fram en förenklad metod för val och utformning av LOD-metod som är anpassad för privata fastighetsägare.

Ett flertal LOD-anläggningar samt förutsättningar kring dessa har undersökts. Studien har gett en grundläggande information och en beräkningsgång som har förenklats, är lätt att följa och som kan anpassas efter befintliga förutsättningar och önskemål. 

Recently it has become more common in the construction of large dams to reuse diversion tunnels as flood discharge tunnels in the final structure. These tunnels handle large flows with the characteristics of open channel flow. When such large hydrological forces act upon a structure there are several problems to be expected. One of these is the occurrence of cavitation, which could have potential hazardous erosion as a consequence. Cavitation is the formation and collapse of bubbles that create a shockwave strong enough to erode the underlying material.

The Baihetan dam is one of the largest hydro power projects in China at present. It has three discharge tunnels that all run the risk of developing cavitation damages. By modelling one of the tunnels using Computational Fluid Dynamics (CFD) it is possible to investigate where in the tunnel structure cavitation is likely to occur.

This degree project assesses the risk of cavitation erosion in the Baihetan tunnel using the static pressure distribution, the velocity distribution and modern cavitation theory. Several modifications of the tunnel – including alterations in the gradient and construction parameters – are simulated in order to investigate if changes in the design can mitigate the cavitation problem. None of the analysed modifications completely eliminate the problem and aeration is recommended to counteract the problem. This study indicates where cavitation might be a problem in the Baihetan tunnel and can be used as a basis for further research.

Partikeldynamik i Luleås dricksvattennät

Water is an essential resource that we today take for granted. The distribution of drinking water is done with pipes in our water distribution network. These pipes have a limited lifetime and at some point they will rupture, with a leak as a result. The leak can lead to major consequences. Some examples are: disturbance in traffics, damage to property, as well as private individuals and businesses that are without water. Another consequence is the cost itself of repairing the leak, which sometimes is the most severe consequence.

To avoid future problems with water leaks, it is important to renew the pipe network. The planning of this renewal is called renewal planning. A method in renewal planning is so-called “risk-based renewal planning”. This method aims to find the pipes that carry the highest risk. A pipe with high risk is a pipe that has high probability of rupturing, at the same time as the consequence of a rupture is great.

Tekniska Verken in Linköping is in charge of the water distribution network in Linköping municipality. In their renewal planning they are working on a new tool, called “Knappen”. The ambition with “Knappen” is to be able to find pipes with high risk with “just one touch of a button”. “Knappen” is a calculation based on a variety of input data on probability and consequence. One of the factors to be used in the calculation is an estimate of the repair cost that the leak causes. This study has resulted in a formula for calculating this cost.

The formula is based on data about past leaks from 2011. The factors that the formula turned out to depend on is: in which land type the leak has occurred, how far the distance is, which repair method has to be used and also the material and dimension of the pipe.

Water is an essential resource, and its significance is growing with the global populationincrease. Historically, Sweden has had ample supplies of clean water, but futurechallenges in drinking water availability cannot be ruled out. To conserve the availabledrinking water, several approaches are possible, one of which is greywater recycling.Greywater refers to wastewater from baths, dishwashing, and laundry. This usedgreywater can be purified and then reused as flush water for toilets.

The purpose of this report is to investigate whether a greywater recycling system isfeasible to implement in an existing building, what investments are required, and whatsavings can be achieved. A greywater recycling system is designed, and a comparison ismade between a technical solution in an existing building versus a new building.Additionally, the potential of greywater recycling and the challenges involved areanalyzed.

In this work, a case study was conducted where a hotel building was analyzed. Theexisting hotel building served as the basis for the design of a greywater recycling systemin both the existing structure and in a theoretical new construction. Calculations of waterflows and pipe sizing formed the basis for the design of the greywater recycling system.Throughout the work, a literature review was conducted to expand the understanding ofthe subject. Furthermore, information was gathered from experts to investigate thegeneral possibilities and challenges of greywater recycling.

The results show that a greywater recycling system is designed the same way in anexisting building as in new construction. However, extensive measures are required in anexisting building when implementing a greywater system, which leads to it not beingoptimally feasible from an economic and sustainable perspective. Preliminary costestimates show that there is a significant economic difference between implementing asystem for recycling greywater in an existing building versus in a new construction. Themost commonly used purification system for greywater is a biological purificationprocess with filtration, which is also proposed in the designed system.

The analysis shows that there is potential for water savings through the recycling ofgreywater for toilet flushing, a method that is not only feasible but also aligns with theUN's goals for sustainable cities and communities. Currently, economic gain is difficult toachieve in a greywater recycling system. Installation and operational costs exceed theeconomic savings of water due to the current low water prices. However, potential futureincreases in water prices could mean that systems with greywater recycling could becomeeconomically advantageous. It is therefore important to continue developing thetechnology and the current laws and regulations concerning greywater recycling, tobroaden the possibilities for the use of recycled greywater.

This bachelor thesis was executed as a Minor Field Study (MFS) in Malolo Lailai Island, Fiji.The Minor Field Study was funded by the state agency Swedish International DevelopmentCooperation Agency (SIDA). The thesis was written during the spring of 2023 at the RoyalInstitute of Technology (KTH) in Stockholm and the project was created and executedtogether with the organisation Corals for Conservation (C4C) located in Fiji.

Coral reefs around the world are degraded due to many different anthropogenic stressors,where climate change is a major one. This has affected the reefs in Fiji as sea temperaturesare rising which is causing corals to bleach. Efforts are being made to restore the reefs whichincludes outplanting and monitoring corals in degraded reefs. As conditions in the seaschange, corals are increasingly exposed to predators and disease. Against this backgroundthis project was created in order to see if outplanting corals inside or close to a Damselfish(Stegastes nigricans) territory makes any difference to the survival rate of the corals. Theresults show that corals outplanted outside of a Damselfish territory has a higher risk ofexposure to predators as well as foragers which leads to a lower survival rate. The conclusionthat was made was that planting corals inside of a Damselfish territory therefore increases thechances of corals surviving.  

Sustainable water recycling and wastewater reuse are urgent nowadays considering water scarcity and increased water consumption through human activities. In 2015, United Nations Sustainable Development Goal 6 (UN SDG6) highlighted the necessity of recycling wastewater to guarantee water availability for individuals. Currently, wastewater irrigation (WWI) of crops and agricultural land appears essential. The present work overviews the quality of treated wastewater in terms of soil microbial activities, and discusses challenges and benefits of WWI in line with wastewater reuse in agriculture and aquaculture irrigation. Combined conventional-advanced wastewater treatment processes are specifically deliberated, considering the harmful impacts on human health arising from WWI originating from reuse of contaminated water (salts, organic pollutants, toxic metals, and microbial pathogens i.e., viruses and bacteria). The comprehensive literature survey revealed that, in addition to the increased levels of pathogen and microbial threats to human wellbeing, poorly-treated wastewater results in plant and soil contamination with toxic organic/inorganic chemicals, and microbial pathogens. The impact of long-term emerging pollutants like plastic nanoparticles should also be established in further studies, with the development of standardized analytical techniques for such hazardous chemicals. Likewise, the reliable, long-term and extensive judgment on heavy metals threat to human beings's health should be explored in future investigations.

Sweden's wastewater treatment plant faces several challenges, one of them is the reduction of greenhouse gases. Nitrous oxide is one of these greenhouse gases, which is formed during the purification of wastewater. Nitrous oxide is 300 times more harmful to the climate compared to carbon dioxide. In addition, it affects the depletion of the ozone layer. At present, it is difficult to measure and estimate nitrous oxide emissions, since several simultaneous processes are taking place on large areas. For the operation of sewage treatment plants to take place in an efficient manner and with an extremely small environmental impact, it is important to understand how nitrous oxide is formed and how the formation processes interact with the other treatment processes and operating parameters.

Emissions of nitrous oxide have been studied at the wastewater treatment plant in Gothenburg. The purpose has been to provide results and measurements from Gryaab AB wastewater treatment plant and to determine which processes give rise to the highest nitrous oxide emissions. Emissions of nitrous oxide emissions have been measured from reject cleaning with the nitrification and denitrification process. Analysis of the results will hopefully be able to help Gryaab AB with further research. As a measurement method, EPA hood measurement was used, which was measured above the water surface in the basins and mobile extractive FTIR was driven around the facility.

The dominant source of nitrous oxide was found to be formed most in the nitrification process. Where the measurements with hood measurement and sampling showed total emissions corresponding to 1.8 tons of N2O / year. The total nitrous oxide emissions from the biological treatment process showed total emissions corresponding to 3.5 tons of N2O /year.

As a conclusion, more measurements with different measurement methods and more research should be done to get a better overview of why and how nitrous oxide is formed. And what measures can reduce nitrous oxide emissions. There is a need for further studies with measurements with different measurement methods on Gryaab AB.