Hydraulic Loading On Test of Nitrogen And Phosphorus Removal From Rural Sewage by Subsurface Constructed Wetlands-ponds Composite System

摘要

Based on the main factor of hydraulic loading, removal of nitrogen and phosphorus and effluent quality of rural domestic wastewater were studied in subsurface constructed wetlands-ponds system in Jiangxi Province. The results showed that there had good processing results on nitrogen and phosphorus'removal by subsurface constructed wetlands-ponds system,especially on removal of phosphorus. In the combined system removal influence of nitrogen and phosphorus were affected by hydraulic loading,it was influenced more significantly for nitrogen removal and had less influence on removal effect of phosphorus relatively.When the hydraulic loading was 72 m~3·m~(-2)·d~(-1), removal rate of TN,NH_3-N,TP were 75.3%,76.08%,86.77% respectively,which was very good for the combined system;removal rate of TN,NH3-N,TP were 42.67%,33.62%,61.72% in the subsurface constructed wetlands; removal rate of TN,NH_3-N,TP were 32.63%,42.46%,25.05% in the ponds.While hydraulic loading was lower,the subsurface constructed wetlands was the control factor for the combined system.With the increasing of hydraulic loading,the ponds was the control factor gradually. In the combined system, effluent quality of TN was superior to the first class B criteria specified in GB 18918-2002(15mg·L~(-1)),effluent quality of NH_3-N was superior to the first class B criteria (8mg·L~(-1)), effluent quality of TP was superior to the case-V waters of surface water quality(GB3838-2002)standard(0.4 mg·L~(-1)) .Research results could be the basis of combined system in Jiangxi Province.