A free water surface constructed wetland in treating sugarcane wastewater

A free water surface constructed wetland stabilized sugar cane wastewater which had received preliminary treatment. About 568 L/s of sugar cane wastewater flowed through a sedimentation basin, then through a canal toward the 5.2 km 2 wetland which contained eight controlled outlets. Wetland waters were monitored near six of the eight outlets for the 65 days of the grinding season and for an additional 4 months. Wastewater pH entering the wetland was about 5.5 and soon increased to the neutral pH. At the end of the factory operating season 95% of each of the mass of TSS and BOD entering the wetland had been removed and then more TSS and BOD were removed after the factory operation ended. Part of the BOD content was from suspended solids, which were susceptible to being trapped in the wetland vegetation and being removed from the water column by sedimentation. © 2011, Baywood Publishing Co., Inc.