Saline municipal wastewater treatment by constructed mangrove wetland

The feasibility of using constructed mangrove wetlands to treat saline municipal wastewater was evaluated in this study. Constructed wetland, acting as an ecological engineering alternative, is capable of reducing NH4+-N\ TN\ TP and COD from saline wastewater. During the 10 months' operating period, the constructed wetland was operated with salinity increasing from 10 to 50 parts per thousands (ppt). When the salinity of wastewater was below 30 ppt, the removal rates of NH4+-N>; TN>; TP and COD were 71.6 79.8%, 75.5-89.6%, 82.7-97.4 and 66.6-85.3%, respectively. The removal rate of COD decreased to about 40% when the salinity increased to 50 ppt. A good performance of COD removal was obtained when the constructed mangrove wetland was operated at loading rate between 12.6-18.9 g m"2 d"1. The preliminary result shows that constructed mangrove wetland for saline municipal wastewater treatment have broad future.