Ecologically engineered system (EES) designed to integrate floating, emergent and submerged macrophytes for the treatment of domestic sewage and acid rich fermented-distillery wastewater: Evaluation of long term performance

Abstract

An ecologically engineered system (EES) was designed to mimic the natural cleansing functions of wetlands to bring about wastewater treatment. EES consisted of three tanks containing diverse biota viz., aquatic macrophytes, submerged plants, emergent plants and filter feeders connected in series. The designed system was evaluated for 216 days by operating in continuous mode (20 l/day) to treat both sewage (DS) and fermented-distillery wastewater (FDW, from hydrogen producing bioreactor). Floating macrophyte system (Tank 1) was more effective in removing COD and nitrates. Submerged and emergent integrated macrophyte system (Tank 2) showed an effective removal of volatile fatty acids (VFAs) along with COD. Filter-feeding system (Tank 3) visualized the removal of COD, VFA, turbidity and color. On the whole the system can treat effectively DS (COD, 68.06%; nitrate, 22.41%; turbidity, 59.81%) and FDW (COD, 72.92%; nitrate, 23.15%; color, 46.0%). The designed EES can be considered as an economical approach for the treatment of both sewage and fermented wastewaters.