Sduty On Treatment Of Rural Sewage Constructed Rapid Infiltration System Of Ecologica Phosphorus Removal

At present, most decentralized sewage in Chinese rural areas are discharged into natural water without treatment. It destructs aquatic ecosystems and causes serious water pollution, such as algal blooms, red tides and other water quality deterioration. It has seriously affected the ecological environment in rural areas and the inhabitants of drinking water safety and health threat. In order to solve the problem of ecological environment in rural areas caused by discharging sewage without treatment, this paper focused on the ineffective removal technology issues of nitrogen and phosphorus by traditional constructed rapid infiltration. Based on the constructed rapid infiltration, we built the separate pool of phosphorus removal for rural sewage treatment. Phosphorus removal was studied mainly by static manner and simulation experiments in the laboratory.First the ecological systems constructed rapid infiltration process has been strengthened. In front of the constructed rapid infiltration, a tank was built for nitrogen removal by microbial nitrification and denitrification. At the back of the main pool, another tank was built for phosphorus removal through adsorption. Finally, the output will be back flowed to the main body of the ecological field constructed rapid infiltration, to adsorb more phosphorus by plants. Then the limestone was chosen as a filler medium by considering the effects on phosphorus removal by comparing the theoretical adsorption capacity, temperature, particle size, pH, background electrolyte concentration, the initial concentration of phosphorus and other factors. At last, the optimum operating parameters of ecological field constructed rapid infiltration system are showed as follows through comparing the experimental parameters of the hydraulic loading and organic loading ratio of wet to dry:the hydraulic load is7m3/m3·d, organic load is0.3kgCODCr/m3·d and the ratio of wet to dry is1:3. At the same time, the parameters of the demonstration project were designed and the size of the main structures are calculated.The results showed that when the influent concentration of phosphorus was4.0mg/L, the effluent phosphorus concentration can be reduced to about0.5mg/L, the removal ratio is90%. The system was stable. It can basically meet the grade A standards of "urban sewage treatment plant pollutant discharge standards " GB18918-2002. At last, through economic analysis of this system, we can get the conclusion that the ecological field constructed rapid infiltration system is an ecological, efficient and low-cost rural sewage treatment technology.