Nitrogen and phosphate mass balance in a sub-surface flow constructed wetland for treating municipal wastewater

摘要: Abstract This paper reports on the feasibility of using sub-surface horizontal flow constructed wetlands to treat municipal wastewater in Hong Kong. Two different hydraulic retention times (10-day and 5-day) types treatments (with without vegetation) were investigated. Better performance planted was obtained both time treatments. Nutrients better removed with plants (DOC 68% 72%; NH4-N 92% 95%; TKN 65% 62%; PO4-P 79% TP 67% 52% for 10-day HRT; 5-day HRT treatments). In unplanted treatments, negative values achieved removal phosphate presence could further polish so concentrations decreased The effluent meet Inland Water A standard, they can be used recreation park Kong (1 mg L−1 NOx; 15 mg L−1 NH3; 1 mg L−1 TP).