Technique And Mechanism Research On New Constructed Land Infiltration Treatment System

The rapid development of small towns accelerates environmental pollution and water shortage in our country. Appropriate treatment and reuse of wastewater become a concern in rural modernization. In this paper, litter-scale experiment was carried out in East Area wastewater treatment plant by using rapid infiltration land treatment system and integrated vertical-flow infiltration system to research the effect of land infiltration on sanitary wastewater of small towns, which supported by the Natural Key Research and Development Programme (Grant No.2003BA808A17).Study of Constructed Rapid Infiltration System (CRI) and integrated vertical-flow infiltration system are just in the initial stage in China. In this study, through experiment, optimizing the operational parameter of the two land infiltration system; running impact of microorganism distribution in the system; pretreatment system were analyzed systematically ; reaction kinetics and mechanism of contamination removal were explored initially.Results are the followings:1. Constructed Rapid Infiltration System:There are great effect of CRI system on operating-drying schedules , hydraulic load, filling thickness and operation durations.When operating-drying schedule was 1:6, CRI system was running normally and stably with high outlet water quality and high capability of bearing shock load. The result showed that selecting hydraulic load in 7.5m/d was suitable. After technically compare, sedimentation process was an ideal pretreatment process, which can be the technical combination of CRI.Outlet concentration of CODcr, TN, NH₃-N and TP in CRI system are negative exponent linear dependence relation with filling thickness.All kinds of microorganisms distributed widely in the infiltration tank, however, the amount and space distribution was different. In amount, aerobic bacteria was two classes higher than Actinomyces, fungi and anaerobic bacteria. In space distribution,...