Constructed wetlands may lower inorganic nutrient inputs but enhance DOC loadings into a drinking water reservoir in North Wales.
The objective of this study was to monitor a newly constructed wetland (CW) in north Wales, UK, to assess whether it contributes to an improvement in water quality (nutrient removal) of a nearby drinking water reservoir. Inflow and outflow of the Free Water Surface (FWS) CW were monitored on a weekly basis and over a period of 6 months. Physicochemical parameters including pH, conductivity and dissolved oxygen (DO) were measured, as well as nutrients and dissolved organic and inorganic carbon (DOC, DIC) concentration. The CW was seen to contribute to water quality improvement; results show that nutrient removal took place within weeks after construction. It was found that 72 % of initial nitrate (N03 (-)), 53 % of initial phosphate (PO4 (3-)) and 35 % of initial biological oxygen demand (BOD) were removed, calculated as a total over the whole sampling period. From our study, it can be concluded that while inorganic nutrients do decline in CWs, the DOC outputs increases. This may suggest that CWs represent a source for DOC. To assess the carbon in- and output a C budget was calculated.
Department of Hydrogeology, Free University of Berlin, 12249, Berlin, Germany. scholz@igb-berlin.de.
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Scholz
School of Biological Sciences, Bangor University, Gwynedd, LL57 2UW, Wales, UK.
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Jones
School of Biological Sciences, Bangor University, Gwynedd, LL57 2UW, Wales, UK.
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West
School of Biological Sciences, Bangor University, Gwynedd, LL57 2UW, Wales, UK.
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Ehbair
School of Biological Sciences, Bangor University, Gwynedd, LL57 2UW, Wales, UK. c.dunn@bangor.ac.uk.
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Dunn
School of Biological Sciences, Bangor University, Gwynedd, LL57 2UW, Wales, UK.
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Freeman
D057919:Biological Oxygen Demand Analysis; D060766:Drinking Water / Q000032:analysis*; D014852:Wales; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods; D060753:Water Quality; D053833:Wetlands
D060766:Drinking Water; D014874:Water Pollutants, Chemical
Carbon budget; Constructed wetland; DOC; Drinking water treatment; Nutrient removal; Surface flow wetland