Application of constructed wetlands on wastewater treatment for aquaculture ponds

A group of constructed wetlands (CWs) were applied to the recirculating aquaculture system. This study assessed the performance of CWs in treating the aquaculture wastewater, examined the water quality condition of aquaculture ponds and the growth and the survival rate of “target” species (Ictalurus punctatus and Megalobrama amblycephala). The results showed that CWs were effective on reducing the concentrations of 5-day biochemical oxygen demand (BOD5, at 70.5%), total suspended solids (TSS, at 81.9%), chlorophyll a (Chl-a, at 91.9%), ammonium (NH4 +, at 61.5%) and nitrate nitrogen (NO3 −-N, at 68.0%). Effect of CWs on phosphate (PO4 3−-P) removal was relatively lower (at 20.0%). The concentrations of BOD5, TSS, Chl-a, NH4 + and TN, TP in the recirculating culture pond were significantly lower than that in the control pond(p < 0.05). CWs could help to increase total yield, survival rate of the “target” species and significantly decrease feed conversion ratio (p < 0.05).