Study of Combined Three-chamber Anaerobic Reactor and Vertical Subsurface Flow Constructed Wetland Process for Rural Grey Wastewater Treatment

The combined three-chamber anaerobic reactor and vertical subsurface flow constructed wetland process was adopted for the treatment of the Changsha County rural dispersed grey wastewater to investigate the feasibility and the removal efficiency. From November 22, 2011 to June 9, 2012, the continuous 192 days operation results showed as follows. When the influent COD_Cr, NH₄⁺-N, TN and TP concentration was 283-684, 3.2-19.5, 13.2-37.4 and 1.2-6.3 mg/L, respectively, the COD_Cr, NH₄⁺-N, TN and TP average removal efficiency was 88.9%, 73.9%, 69.8% and 73.9% accordingly under the operation conditions of the anaerobic reactor 75 h HRT and the vertical constructed wetland 30 h HRT. The effluent average concentration of the four indexes was 52, 2.1, 5.1 and 0.7 mg/L, respectively, which could meet the Ⅰ-class B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002).