Study On Discharge Characteristics And Treatment Technology Of Rural Domestic Sewage In Western Anhui

In recent years,with the implementation of a series of projects,such as the comprehensive revitalization of rural areas and the construction of ecological livable and beautiful villages,rural infrastructure and farmers’ living conditions have been improved.However,the treatment of rural domestic sewage has not been properly treated,coupled with the lack of corresponding discharge standards,so the treatment is difficult.In this paper,combined with the existing sewage treatment process in Western Anhui mountain area,through the investigation of the natural geographical conditions,population,economic conditions,living habits,sewage output characteristics,analysis of different sewage treatment processes,methods,proportion and treatment effect,etc.,the paper carries out fuzzy comprehensive evaluation on the sewage treatment process,and puts forward technical optimization and management measures for the selected area’s sewage treatment process Optimization.The main work and conclusions are summarized as follows.(1)The output characteristics of rural domestic sewage in Western Anhui.1)The water consumption in summer is significantly higher than that in winter.The daily water consumption of the four villages is not stable,and the water consumption peak appears in the morning,middle and evening respectively.Therefore,the sewage discharge presents the characteristics of intermittent and unstable water volume,among which Pingjing village has the highest water consumption per capita and Shiguan village has the lowest water consumption It is found that there is a correlation between water consumption per capita and population aggregation in summer.2)The concentrations of NH3-N,CODcr,TN and TP of kitchen waste water,bath wastewater and laundry wastewater in four villages were in accordance with normal distribution.The concentration of CODcr in sewage of each village was generally high.The concentration of pollutants in kitchen waste water was the highest and that of bath wastewater was the lowest.The correlation was analyzed It was found that there was a positive correlation between TN concentration of kitchen waste water and population and per capita water consumption,while there was a negative correlation between TP concentration of bathing sewage and per capita water consumption in summer.3)The rural domestic sewage treatment technologies applied in the mountainous areas of Western Anhui mainly include A/A/O process+wetland,integrated purification tank and soil purification tank.The water system in the study area is relatively developed,and most of the villagers’ gathering points are rich in water.In the treatment of rural domestic sewage,non-point source pollution and protection of local rivers should be considered.(2)Optimization method of applicability treatment process for rural domestic sewage in Western Anhui Province.The evaluation results are as follows:A/A/O process>soil purification tank>integrated purification tank.The results of economic index maximization were:septic tank>constructed wetland>high load anaerobic reaction.The most simplified evaluation results of technical indicators were:septic tank>constructed wetland>high load anaerobic reaction.The results of strict evaluation of management indicators were as follows:A/A/O process>soil purification tank>integrated purification tank.(3)Empirical evaluation and suggestions on the treatment effect of domestic sewage in mountainous area of Western Anhui Province.Taking Xinhu village of Xiangchang town,which has the largest population concentration,as an example,this paper analyzes the sewage discharge,sewage quality and the treatment effect of three format septic tanks.The main conclusions are as follows:1)the sewage discharge in summer is 18.21-28.73 m3/d,and that in winter is 13.72-21.65 m3/d The amount(30 m3/d)basically contains the local daily sewage discharge;after the septic tank is discharged,it is connected to the domestic sewage treatment facilities by pipeline,and the influent NH3-N concentration basically meets the requirements of the sewage treatment facilities,the influent TP concentration exceeds the requirements of the sewage treatment facilities,and the influent COD concentration exceeds the requirements of the sewage treatment facilities.For similar rural areas with high water consumption and low concentration of sewage,when designing sewage treatment facilities of corresponding scale,the hydraulic retention time can be appropriately reduced.In economically underdeveloped areas,ecological wetland treatment can be adopted,and nitrogen and phosphorus wastewater can be reasonably used as crop nutrient supply.