Study On The Treatment Of Rural Domestic Sewage By Combined Application Of Reflective Pool And Constructed Wetland

As a rural sewage treatment process Reflective tank-artificial wetland combination process,is conducive to solving the problem of rural sewage treatment and other difficult.It is used not only to make the sewage to meet the discharge standards,improve the living environment of rural residents,improve the quality of life,but also to avoid non-compliance of sewage into the nearby river,causing water pollution,affecting the quality of groundwater,endangering the health of residents.The study of the anti-filter-artificial wetland process can provide strong technical support for domestic sewage treatment and promote its wide application in rural areas.Based on the design and construction of the anti-filter-artificial wetland combination process,the stability of the operation of the single filter tank is studied.The influence of the ratio of air to water,the time of water retention and the temperature on the filter tank are analyzed,and the optimum operating conditions.At the same time,the stability of the constructed wetland was studied,and the influence of hydraulic load and temperature on constructed wetland was analyzed.The effluent samples of each treatment unit were collected,and the effect of the combined process on the effluent was analyzed.The contribution of each unit to the removal rate of sewage was determined.Based on the first-order dynamic model,the pollutant reaction kinetics model was established on the basis of the first-order dynamic model.The main results and conclusions are as follows:(1)The removal rate of ammonia nitrogen and organic matter reached 70% and 65%,respectively,after 30 days of treatment.(2)The removal rate of total phosphorus and ammonia nitrogen was 74.5% and 74%,respectively,and the removal efficiency of total nitrogen was only 38%.Gas and water ratio,hydraulic retention time,temperature can affect the anti-filter treatment effect.With the increase of gas-water ratio,the removal rate of pollutants on the filter showed a tendency to rise first and then,and the best gas-water ratio was 2:1,considering the effect of treatment and economic factors.And the removal rate of nitrogen,total phosphorus and ammonia nitrogen were 70.37%,59%,80% and 75%.With the increase of hydraulic retention time,the removal rate of pollutants increased with the filter,combined with economic considerations,to determine the best residence time of 3h.The removal rates of organic matter,total nitrogen,total phosphorus and ammonia nitrogen were 77.37%,61.49%,78.12% and 74.51%.According to the analysis of the data,a group of low temperature and a group of high temperature contrast test were selected to study the effect of temperature on the treatment of the filter.To determine the high and low temperature,the removal rate of nitrogen was decreased,and the average removal rate was 25% and 40%.The optimum operating conditions for the filter tank are: water temperature is 24 ? ~ 27 ?,pH is 7.5 ~ 8.5,gas to water ratio is 2: 1,hydraulic retention time is 3h.(3)The effect of artificial wetland on the removal of pollutants is stable,and the removal efficiency of TN is better than that of filter.The removal rates of ammonia nitrogen,organic matter and total phosphorus in constructed wetland were 76.81%,70.22% and 72.93%.The hydraulic load and temperature are the important factors that affect the effect of the constructed wetland.With the increase of the hydraulic load,the removal rate of the pollutants is increased.When the hydraulic load is 0.12m3 /(m2 · d),the removal efficiency of ammonia nitrogen,organic matter and total phosphorus is 71.87%,71.32% and 72.55% respectively.When the hydraulic load continues to increase,Nitrogen content decreased;too high and too low temperature will reduce the removal rate of pollutants in wetlands.(4)The combination process has good effect on the removal of pollutants and strong resistance to stress.It is suitable for the treatment of rural domestic sewage,in which organic matter,Total phosphorus ammonia nitrogen is close to complete removal.The removal rates of ammonia nitrogen,organic matter,total phosphorus and total nitrogen were 92.59%,90.05%,91.42% and 67.56%.In the combined process,the removal rate of pollutants in different treatment units is different.The sedimentation tank and anaerobic tank mainly play the role of pretreatment.The filtration tank plays a big advantage in the removal of ammonia nitrogen and total phosphorus.The removal rate of ammonia nitrogen and total phosphorus is 70.11% and 71.26% respectively.Artificial wetlands have an advantage in the removal of total nitrogen,and one of the best wetland treatment effect.The removal rate of Total nitrogen was 30.4%,and the removal rate of Total nitrogen was 19.35%.(5)The kinetic model of pollutant reaction in submerged artificial wetlands shows that the reaction kinetics model of Total phosphorus and ammonia nitrogen can well reflect its decay law.