Efficiency of a constructed wetland for retention of sediment associated phosphorus
2011 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 674, no 1, 179-190 p.Article in journal (Refereed) Published
A constructed wetland (2.1 ha; 2% of catchment area) in southeast Sweden, in a catchment with 35% arable land on clay soils, was investigated with respect to phosphorus (P) retention, focusing on particulate P (PP) and sediment accretion. The aims were to i) estimate P retention and identify the dominating retention processes; ii) investigate how well estimates of P retention based on inflow-outflow measurements compared with the amount of P accumulated in the sediment. In- and outflow of P was measured during four years with continuous flow measurements and flow proportional weekly composite samples. P in the accumulated sediment was estimated based on core samples and analyzed using sequential fractionation. Total P load during four years was 65 kg/ha and intensive sampling events detected 69% as PP. Based on inflow-outflow estimates the mean P retention was 2.8 kg/ha/yr, or 17%, but the amount of P accumulated in the inlet zone equated 78% of the TP load. This discrepancy showed the need to add studies of sediment accumulation to inflow-outflow estimates for an improved understanding of the P retention. The dominating P forms in the sediment were organic P (38%) and P associated with iron or aluminum (39%), i.e. potentially mobile forms. In areas colonized by Typha latifolia, the amount of P in the upper sediment layer (390 kg) was more than double the total P load of 136 kg. Cycling and release in those areas is a potential source of P that deserves further attention.
Place, publisher, year, edition, pages
Springer , 2011. Vol. 674, no 1, 179-190 p.
Constructed wetland, long-term retention, diffuse pollution, particulate phosphorus, sediment accretion, sediment phosphorus fractions
IdentifiersURN: urn:nbn:se:liu:diva-67880DOI: 10.1007/s10750-011-0728-yISI: 000293163900013OAI: oai:DiVA.org:liu-67880DiVA: diva2:413995
The original publication is available at www.springerlink.com:
Karin Johannesson, Jonas Andersson and Karin Sundblad-Tonderski, Efficiency of a constructed wetland for retention of sediment associated phosphorus, 2011, Hydrobiologia, (674), 1, 179-190.
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