STUDY ON GARDEN PLOT SYSTEMS FOR DECENTRALIZED WASTEWATER TREATMENT IN RURAL AREAS OF THE YANGTZE RIVER DELTA, CHINA

As a modified land treatment system, the garden plot system (GPS) has considerable potential for rural decentralized wastewater treatment In this study, two GPSs were established - one in the Caohuang village for domestic sewage (DS) treatment and the other in the Houhong village for livestock wastewater (LW) treatment. Both GPSs exhibited high treatment efficiency. The outflow of DS treated by a GP S can be discharged into rivers and lakes that have a lower dilution capacity, whereas the outflow of LW treated by a GPS can potentially be utilized as liquid fertilizer. An investigation of three villages in the town of Wanshi found the amount of discharge in the area averaged approximately 55.0 L/p/day, and water quality monitoring showed the concentration of LW to be much higher than that of DS. We estimate that in the rural areas of the Yangtze River Delta, DS can be fully accommodated by the area's garden land. Accordingly, based on the village GPS studies, a decentralized wastewater treatment model was constructed for rural areas in the Yangtze River Delta to support both wastewater utilization and environmental protection.