Experimental Research Of Centralized Sewage Treatment Technology In Rural Areas (Community)

With the improvement of the quality of rural life,the sewage treatment in these areas has been treated improperly and a series of environmental problems occured due to the lack of network construction.Develop a technology that can remove pollutants in domestic wastewater effectively and economically has become the key to solve the rural sewage treatment in China.In that case,this paper carried out experimental research on anaerobic pretreatment,aerobic treatment,artificial wetland and monitoring of the aerobic wastewater treatment demonstration project in a community to provide basis for the combinatorial technology.Anaerobic pretreatment was carried out with four small buckets of static experiment,divided into the mud experimental group and the non-mud experimental group,and the experiment lasted 175 days.The restlus were as follows: under the condition of COD of 480~550mg/L,TN of 85~110mg/L,NH3-N of 75~100mg/L,TP of 6~7mg/L in the influent,the CODCr in the effluent of the two group both reached the second discharge standard of pollutants for municipal wastewater treatment plant(GB18918-2002),the corresponding average TN removal were 43.75% and 30%,the corresponding average NH3--N removal were 43.% and 26%,and TP were barely removed.The aerobic test carried out four small buckets oxygen-filled experiments and one small bucket of oxygen loss.Aerated domestic wastewater with the aeration quantity of 160L/h,when DO doesn't raised,stop the aeration,and the oxygen deficit experiment started.The results were as follows:when the aeration were 160L/h and 80L/h,DO,pH,ORP and temperature of the system raised quickly,the maximum of the above indicators for the experimental group of 80L/h was smaller than that of the group of 160L/h.When control the aeration at 40L/h and 20L/h for 10 days,the concentration of dissolved oxygen increased to 3.5mg/L slowly after 24 h and didn't change.The COD,NH3-N,TN and TP all continued to decline,The nitric nitrogen kept rising,the pH went up and then went down,the temperature and the ORP went up.In the experiment of oxygen loss,the dissolved oxygen,temperature and ORP of the system fell rapidly,and the temperature raised in a staircase.The artificial wetland experiment was carried out in four kinds of condition,the results showed that,under the condition of COD of 425~450mg/L,NH3-N of 60~80mg/L,TN of 65~85mg/L,TP of 1.6~1.8mg/L in the influent,the COD in the effluent was 18mg/L~100mg/L,the average COD removal was 86.5%,the NH3--N in the effluent was 12mg/L~40mg/L,the average NH3--N removal was 62.9%,the TN in the effluent was 12mg/L~39mg/L,the average TN removal was 66%,the TP in the effluent was 1.18mg/L ~1.65mg/L,the average TP removal was 16.8%.The monitoring results of the aerobic wastewater treatment demonstration project in Xi 'an showed that,COD concentration in the inlet water was 770mg/L ~ 1100mg/L,ammonia nitrogen concentration in the inlet water was 80mg/L ~ 150mg/L,and TP concentration in the inlet water was 3mg/L ~ 10mg/L.The removal rate of COD was 60% ~ 80%,the removal rate of COD was good,but the removal rate of ammonia nitrogen and total phosphorus were not good.