Performance of Anaerobic Stage-Constructed Wetland Integrated in Treatment of Low-Concentration Domestic Sewage

Abstract

Prompted by the constructed wetland without long-term stable operation and anaerobic baffled reactor (ABR) with higher suspended solid (SS) removal rate, an anaerobic stage-constructed wetland integrated sewage treatment system was designed and applied to treat low-concentration domestic sewage from campus. The hydraulic retention times (HRTs) of anaerobic stage and constructed wetland were set as HRT1, HRT2 by our research. All the trials lasted 30 months, and the results of trial indicated that SS removal rate of the ABR stage was at least 82% under the condition that HRT1 ≥20h. At（ 22±2）°C, under the conditions that HRT1=45h and HRT2=15h, the COD, TN, TP removal rates of integrated wastewater treatment system could be over 82.38%, 76.75% and 71.29%, respectively. Based on the results of trial, the operational life of constructed wetland integrated with ABR was evaluated that at least 4 times than that of individual constructed wetland, and the mechanisms of higher efficacy and long-term stable operation of integrative sewage treatment system in treatment of low-concentration domestic sewage from campus were owed to high efficient SS removal rate at ABR stage.