Premium
Phosphorus Removal Processes in a Wetland after a Decade of Receiving a Sewage Effluent
Author(s) -
Cooke James G.
Publication year - 1992
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1992.00472425002100040032x
Subject(s) - wetland , effluent , sewage , sink (geography) , environmental chemistry , deposition (geology) , phosphorus , environmental science , constructed wetland , sediment , hydrology (agriculture) , environmental engineering , chemistry , sewage treatment , ecology , geology , biology , paleontology , cartography , geotechnical engineering , organic chemistry , geography
A study was made of the processes leading to phosphorus (P) removal in a wetland that received a high load of sewage‐P for over a decade. The amounts of P accounted for by sediment deposition, sorption to detrital material, and uptake by above ground biomass were compared with the mass of P entering and leaving the wetland system. Phosphorus deposition was shown to be the most important sink for P with rates of up to 30 g P m −2 d −1 being recorded. The pronounced spatial distribution of deposition as well as laboratory experiments indicated that P deposition occurred predominantly by reaction between sewage‐wetland waters (high in P, alkaline pH) and natural wetland waters (high in Fe and Al, acid pH) at or immediately below confluences joining their flow streams. Studies on P mass transport showed that the P removal rate (28–70%) was considerably greater than published values suggest could be predicted for this highly loaded (≃34 g P m −2 yr −1 ) system. It is suggested that the wetland configuration, whereby the flow from a relatively small area of sewage‐impacted wetland, is joined by waters from much larger unimpacted wetlands, is the reason for the relatively large P removal in this system. The relative magnitudes of P sinks in this study are different enough from other studies to suggest that the present level of P removal in this wetland is sustainable.