[Effects of constructed wetlands on treating with nitrogen and phosphorus in wastewater from hoggery].
摘要
Using plant species Vetiveria zizanioides (VCWS) and Cyperus alternifolius (CCWS) respectively, two constructed wetlands (CWS) with size of 1.0 m x 0.5 m x 0.8 m were established. The purifying function and its change pattern among different seasons, influent concentration and hydraulic retention time (HRT) of CWS on nitrogen and phosphorus in wastewater from a hoggery was studied throughout four seasons in the year. The results showed that the effects of HRT and wastewater concentration on the removal rate of NH3-N and S-PO4(3-) were obvious in both VCWS and CCWS. High removal rates of NH3-N and S-PO4(3-) were obtained in CCWS and VCWS in spring. Significant removal of TN in wastewater existed in CCWS and VCWS in autumn, while significant removal of TP in wastewater existed only in VCWS. The removal of TP or S-PO4(3-) against the HRT in CWS followed exponential function. The rates of P removal in winter and summer changed with the influent concentrations. Under the same HRT, the change of S-PO4(3-) concentrations in outflow against the influent concentration followed a linear relationship.