[Purification efficiency of vertical-flow wetland system constructed by cinder and turf substrate on municipal wastewater].

Vertical-flow constructed wetlands (VFCWs) system not only has a higher hydraulic loading rate (54-64 cm.d-1), but also has a good removal efficiency for organics, ammonia nitrogen (AN) and total phosphorus (TP). The removal efficiencies of COD, BOD5, AN, and TP for septic tank effluent were 76-87%, 82-92%, 75-85% and 77-91%, respectively, and the average effluent concentrations of COD, BOD5, AN, and TP in the treated effluent were less than 60, 20, 25 and 2.0 mg.L-1, respectively. A comparison of planted and unplanted columns showed that plantation of Cyperus alternifolius could increase the removal rates of AN, TN, and TP by 2-3%, 4-6%, and 10-14%, respectively.