Feasibility of contact aeration method for small-scale domestic wastewater treatment system in rural China

This study examines the feasibility of the contact aeration method for utilisation in small-scale domestic wastewater treatment facilities in various rural areas of China, where the national government starts to address the water pollution issue. Three pilot facilities using the contact aeration method with different capacities were constructed, operated and monitored in Chongqing city and Jiangsu province. In order to evaluate the feasibility of the constructed facilities, the quality of treated wastewater and the operational cost were monitored. Results obtained from the monitoring showed that BOD and COD effluent concentrations achieved quality targets in all facilities. As for the other pollutants, quality targets were met for most of the period. Operational costs of facilities bettered those set for the facility in the town of Baiyang and new village of Zhaojia, but exceeded them for the facility in the village of Dongbei. The main reasons for the differences were the electricity billing system and operational system for each facility. In order to promote small-scale aeration-based domestic wastewater treatment plants in rural China in the future, the issue of what constitutes efficient facility maintenance first needs to be addressed.