| Statistics showed that the sewage quantity was about8billion ton every year in countryside of China presently. Since scattered villages in China were lack of fund and poor awareness of wastewater treatment, the rural domestic sewage was directly discharged to the surface water and affected the rural water quality seriously. So it is very important and urgent to improve a wastewater treatment technology for rural domestic sewage treatment.In view of the situation mentioned above, aroused by these combined process of up-flow anaerobic biofilter(UAF) and greenhouse constructed wetland was used to treat the rural domestic sewage, and its characteristics and effects were studied.The major contents selecting UAF as anaerobic process of wastewater treatment and greenhouse constructed wetland as a subsequent aerobic treatment process, the optimal working conditions of the two processes in the treatment of low concentration domestic wastewater were investigated respectively; Effects of the combined process of UAF and greenhouse constructed wetland in domestic sewage treatment were discussed.Results are shown as follows:(1)The optimum hydraulic retention time for UAF was12h, volume loading was0.632～0.936kgCOD/(m3-d), the average removal ratio was56%for COD,68%for BOD5, and91%for SS;(2)Greenhouse constructed wetland was cultivated by continuously adding dilute domestic sewage. The input water COD concentration was kept110～130mg/L, under the conditions of the outdoor temperature was kept-5～10℃(in winter and spring), indoor temperature was kept10～30℃, and sunshine is sufficient, the HRT of the greenhouse constructed wetland was3days, the average removal ratio was49%for COD,53%for BOD5,37%for SS,63%for NH3-N and46%for TP;(3)Under the above appropriate conditions, the sewage treatment effects of the combined process of up-flow anaerobic biofilter and greenhouse constructed wetland were ideal. The combined process showed excellent removal ratio was75%for COD,84%for BOD5,93%for SS,63%for NH3-N and46%for TP. Except TP, the other major indices of effluent were qualified to the I-class B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002). |
