Lab-Scale Study On Two Stages Constructed Rapid Infiltration System Applied In Livestock Husbandry Wastewater

Constructed rapid infiltration(CRI) system is a whole new biology treatment system,developing step by step from the base of traditional land treatment by ZHONG Zuo-shen of China University of Geosciences Beijing,currently CRI is commonly used to treat domestic wastewater and slight concentration of river. In this article,we carry on an improvement on traditional constructed rapid infiltration system,ventilate a layer in the appropriate position, turn it into two parts,which called two stages constructed rapid infiltration system.The main contents researched in this paper are as follows:First, studying the treatment of livestock husbandry wastewater by two stages constructed rapid infiltration system;Second, acquiring the principal oxygen restoration process through researching internal system gas pressure change;Third, carrying on dehydrogenase activity research. Main conclusions are drawn as follows:1.The result of experiment shows that it will produce good effect of the treatment of livestock husbandry wastewate(rCOD is 1500mg/L,ammonia nitrogen is 65mg/L,phosphorus is 19mg/L)by two stages constructed rapid infiltration system. The average effluent concentration COD is under 100mg/L and the removal rate is 95%; ammonia nitrogen is under 3mg/L and the removal rate is 97%;phosphorus is 1mg/L and the removal rate is 95%.2. The time required for oxygen restoration process is related to the upper porosity and length distance from the surface,the greater porosity and the shorter from the surface, the faster of oxygen restoration rate.3.The existence of ventilation layer leads to the formation of capillary water layer on its top,which may reduce the effect of flow rate and provide good protection for the oxygen restoration process of water flow through the ventilation layer.4. The liquid carries through gas-liquid exchange in ventilation layer,and because of small resistance by film,the liquid can dissolve more oxygen under the effect of oxygen concentration difference in the gas-liquid interface,which provides good protection for sewage entering the second part of the degradation process.5. With a Ventilation layer in proper position,two stages constructed rapid infiltration system appears a area of higher dehydrogenase activity both in the upper and in the bottom,which effectively raise the pollutants effect.