Experimental Research On Treatment Of Rural Domestic Sewage By Multilayer Artificial Soil Infiltration System

Rural domestic sewage has the characteristics of scattered sources,large fluctuations in water quantity and quality,and strong biodegradability.It is not suitable to imitate the way of large-scale urban sewage collection and centralized treatment.Therefore,it is important to study suitable rural domestic sewage treatment technology according to local conditions.social significance and application value.The traditional soil infiltration system for domestic sewage treatment has the characteristics of small investment and simple operation and maintenance,which is suitable for rural areas,but has problems such as low denitrification efficiency and easy blockage.For this reason,the paper systematically studies the effect of multi-layer artificial soil infiltration system on rural domestic sewage by using peat-zeolite packing and changing the water flow operation mode on the basis of the traditional soil infiltration system and using different aeration methods and aeration amounts.processing effect.1.The test runs for 26d to complete the startup of the system.The removal effects of four indicators of effluent COD_Cr,TP,NH₄⁺-N and TN were relatively stable.2.Three kinds of hydraulic load tests were carried out.The results showed that:under the condition of hydraulic load of 0.08 m/d and dry-to-wet ratio of 3:1,group 3#was the optimal treatment group,and the effluent removal rates of COD_Cr,TN,TP and NH₄⁺-N were 85.39%,55.80%,94.33%and 87.59%,respectively.The effluent concentration has reached the Class A standard of"Pollutant Discharge Standards for Urban Sewage Treatment Plants".3.The optimal basic working conditions were improved by the diversion operation,and 12 groups of diversion operation tests were carried out.The diversion test results showed that the TP and TN indexes of the effluent from the diversion operation test increased compared with those before the diversion;the NH₄⁺-N and COD_Cr indexes decreased,among which The COD_Cr index decreased more significantly.The overall treatment effect is better when the split ratio is 1:2 and the lower split is used for split operation.The average removal rates of COD_Cr,TN,TP and NH₄⁺-N in the optimal group were 70.23%,58.50%,81.58%and 86.46%,respectively.4.Using different aeration methods and aeration rates,24 sets of tests were carried out.The results showed that:under the setting of intermittent aeration-aeration rate of0.5L/min,the COD_Cr,TN,TP and The average removal rates of the four indicators of NH₄⁺-N were 86.51%,59.89%,85.63%and 85.77%,respectively.The removal effect of TN was the best,but the removal effect of NH₄⁺-N and TP decreased.