Study On The Treatment Of Rural Domestic Sewage By TBO Technology

Rural domestic sewage has become the main source of pollution in rural areas.In the survey of rural domestic sewage of three different developing regions in Jinzhai County,it is found that the rural domestic sewage is related to the regional development level,living habits and other factors.The water quality and water quantity of rural domestic sewage is changed greatly,and the water quantity usually has three peaks in early,mid and night,small in scale and difficult to collect.With the intensification of environmental pollution in rural areas and the increase in the proportion of sewage,the treatment of rural domestic sewage has been imminent.The TBO technology is used to deal with rural domestic sewage.The effluent can reach the"Urban sewage treatment plant pollutant discharge standards"level A standard limit.The average removal rates of COD,NH₃-N,TN and TP were 79.68%,73.54%,72.86%and 88.48%,respectively.The key issues of TBO technology are also studied:grading analysis of gravel and soil,selection of filler layer,selection of filler layer thickness,selection and preparation of filler,selection of water supply mode and selection of hydraulic load.The results show that sand in fillers is fine sand,soil is coarse-grained soil,the number of filler layers has no significant effect on the treatment effect.The thickness of filler should be 25cm,and packing sand ratio with 4:1-4.5:1 is appropriate,the more the water distribution is,the higher the utilization rate and processing capacity of the TBO system.The effect of influent load on the removal efficiency of NH₃-N was significant,and the effect of COD,TN and TP was small.Considering the effect of treatment with TBO system?engineering cost and other factors,the water load should be 2T/?m²·d?.Combined with the key problem of test results,to design the improving TBO system structure,analyzes the test for more than 3 months.The effluent not only reached the"urban sewage treatment plant pollutant discharge standard"?GB18918-2002?in a A standard,the average removal rate of COD,NH₃-N,TN and TP increased by 1.31%,14.15%,3.85%and 2.58%respectively.and the effluent COD can be less than 40mg/L.NH₃-N,TP value is the standard value of about 1/2.The structure of the improved TBO system is simple,the construction is convenient,the cost of the project is low,and the area is small,the effluent U tube improves the reoxygenation capacity of the system.The TBO technology was applied in the sewage treatment works of Jinzhai County Tiantangzhai and Baitafan town,respectively.the effluent effect both met the corresponding design standard and remained stable at low temperature.A 200T sewage treatment plant has a total investment of about 500 thousand,and the construction period is only 30 days.The daily maintenance only needs to regularly clear up the garbage,and the daily treatment of 1 tons of sewage covers an area of2M².TBO technology is a new kind of ecological treatment system covers an area of small,less investment and cost,easy operation and maintenance,low operation cost,and good pollutant removal effect is proved to be a suitable rural decentralized sewage treatment technology,provides technical guidance for rural sewage treatment.