Pilot Study On Rural Domestic Wastewater Treatment Using The Combinatorial System Of ABR/Simulant Wetland Packed Bed

As an important part of rural non-point source pollution, rural domestic wastewater has not been effective controlled and managed with its large,scattered,not manageable and other characteristics. It is an environmental problem which is urgent to be solved in our country. According to the actual situation of rural areas, the thesis put forward the idea of combinatorial ABR/Constructed Wetland to treat rural domestic wastewater. The processing method have the features of simple structure,convenient operation and management,prominent ecological and environment benefit,a spot of investment and so on. On the basis of theory analysis and experimental research to treat rural domestic wastewater with the combinatorial system, the thesis come to a decision, which is that the treatment of combinatorial ABR/Constructed Wetland is used to treat rural domestic wastewater is feasible. The main conclusions of the research are as follows:(1)During the period of experimentation analysis,the hydraulic retention time(HRT) of ABR was shorten from 15h to 4h, the removal rate of COD in the reactor presented the trend of low-high-low. When the hydraulic retention time(HRT) was 8h, the volume load was 1.1kgCOD/(m3·d), it achieved the best removal effect of COD, the removal rate of COD retained tiptop, the average removal rate was 87.3%;(2)In low temperature conditions, ABR was running in the best HRT, with the temperatu-re lower, the removal rate of COD had declined slightly, only from 93.2% to 84.5% during temperature decreasing from 37℃to 24.8℃;(3)ABR has strong resisting hydraulic loading ability, exerting about 100% hydraulic impact loading, continueing 4h, when withdrawing the impact loading, after 4h, the removal rate of COD of the reactor came backed the prevenient level basically;(4)ABR also has strong resisting organic loading ability, exerting 130% organic impact loading, continueing 6h, the removal rate of COD of the reactor come backed the prevenient level basically;(5)During the first period of Simulant Wetland Packed Bed running, hydraulic loading was only 6cm/d, the average removal rate of COD,NH4+-N,TP was respectively 36.5%,69.9%,78.2%, after three months, the hydraulic loading was advanced to 10cm/d, the average removal rate of COD,NH4+-N,TP was respectively 54.8%,30.9%,38.3%;(6)The system of combinatorial ABR/Simulant Wetland Packed Bed disposed of rural domestic wastewater, when the hydraulic loading was only 6cm/d, the average removal rate of COD,NH4+-N,TP was respectively87.7%,73.7%,79.8% in the combinatorial system, now COD,NH4+-N,TP of effluent all achieved secondary standard of《Sewage Comprehensive Emissions Standards》, after three months, the hydraulic loading was advanced to 10cm/d, the average removal rate of COD,NH4+-N,TP was respectively 90.8%,37.6%,42.2%, except TP, COD and NH4-N also achieved secondary standard of《Sewage Comprehensive Emissions Standards》;(7)The system of combinatorial ABR/Simulant Wetland Packed Bed disposed of rural domestic wastewater, ABR achieved corking removal effect of COD, but the removal rate of NH4-N,TP were very limited; Simulant Wetland Packed Bed was just the opposite, when the both were made up, they could give full play to their respective advantages to ensure rural domestic sewage discharging up to the standard.