The Exprimental Study On The Treatment Of Scattered Wastewater Using Constructed Rapid Infiltration Technique In Northeast Towns And Villages

With the rapid development of social economy, population increasing and theurbanization process accelerating, our country's problems of water also seemsparticularly outstanding, it is mainly shown in two aspects: that is the shortage ofwater resources and water environment pollution, one of the most serious problems iswater pollution. The ecological treatment mode can treat sewage nearby, theconstruction of facilities is flexible and the investment is small.Therefore theecological treatment can be used as a beneficial supplement of Sewage concentrationprocessing mode and it has important significance. CRI sewage treatment system isconsidered as a kind of ecological engineering or biological-ecological treatmenttechnology.CRI system has a good effect on sewage and polluted water of river. Comparingwith the traditional treatment of sewage, the cost of CRI system, which includesconstruction and operation cost is lower, the effect of its yielding water is better andno activated sludge emerges. Besides the operation of CRI system is more simple andmore stable etc.Land processing system is using soil-sewage treatment and the function of plantsystem to achieve processing target. Land treatment system of contamination removalprocess including soil filter interception, physical and chemical adsorption, chemicaldecomposition and precipitation, plants and microbes ingestion, the oxidation anddegradation of microorganisms, evaporation etc. Land treatment system process canbe divided into three basic types: slow filtration (SR), fast filtration (RI), surface flow(OF). The main difference lies in the corresponding sewage hydraulic loading anddifferent hydraulic path. Constructed Rapid Infiltration System(CRI) is a new type ofland treatment technology based on Rapid Infiltration System(RI). It uses artificialpacking to improve hydraulic loading and guarantee the quality of the output waterprocessing.For the northeast towns and villages, sewage treatment should go the way of theprocessing of miniaturization and in situ, following the principles of "two low and onegood" which means the lower cost of both one-time investment and dailymanagement expenses and the better t treatment effect. Therefore the study is mainlyon the CRI system treating the sewage in the northeast.In this paper, we discussed the removal efficiency and purification mechanism of CRI system and analysed some strengthening measures to ensure removal efficiency,enhance the stability and prolong the service life. And we points out the domain andthe development trend of CRI system.In this experiment,by the means of comparing different parameters and exploringthe hydraulic load cycle, water hydraulic loading and filter layer thickness, it isconcluded the optimum operation parameters of CRI system, that is the hydraulicloading is40cm/d, the wet to dry ratio is1:2, the hydraulic loading cycles for floodedis8h and the fall work is12h. The operation results show that CRI has a higherremoval efficiency, which can achieve95.0%, not only to NH4-N but to CODCrandTP, removal rate can reach82.3%and80.4%respectively. The system runs stably,and the effect is good. The removal effect of natural river sands was good atbeginning, however the efficiency gradually decreases with time. The efficiency ofceramsite and quartz sand removing contamination is very stable, but the effect is notgood, especially quartz sand, it's removal rate of NH4-N is almost zero. The removalefficiency of volcanic rocks is moderate. The zeolite is the best in removingcontamination, which it's highest removal rate can reach98.20%,93.17%and95.53%for NH4-N, CODCrand TP respectively.