The New Decentralized Rural Sewage Treatment Process Design And Practical Application Research

In recent years,with the rapid development of agricultural economy,the problem of rural non-point source pollution has become more and more serious,and the rural domestic sewage pollution is one of the main sources of rural non-point source pollution.Most of the rural areas do not have a complete set of network channels and domestic sewage treatment facilities,the sewage is taken directly to the nearby natural water,which has a very serious impact on the normal production and living in rural areas.So this paper according to the characteristics of rural domestic sewage emissions,considering the low investment in the construction of rural areas,small operation cost,easy to operation and management and other factors,research and design a new type of rural life sewage decentralized treatment process and the process application in current rural area sewage decentralized treatment and able to meet the future development trend.According to the current rural sewage biological treatment distributed processing process of comparative analysis and literature research to determine the market recognized degree is high and the relative stability of the process of biological contact oxidation process as a new type of rural life sewage decentralized treatment process design of the basic technology,and in this process is the basis for design and improvement.According to the contact oxidation pool denitrification capacity shortage,according to the design theory of biological nitrogen removal in front of the anoxic tank,through nitrification liquid reflux strengthen nitrogen removal in sewage treatment system,at the same time improve the reflux ratio and the increase of hydraulic load under the premise,according to the biological contact oxidation of the effluent suspended solids(SS)deficiencies exceed the standard and anti hydraulic loading capacity,sedimentation tank design integrated biological innovation contact oxidation,biological contact oxidation tank and sedimentation tank is communicated with the bottom of the bottom of the tank,promote the use of slope from precipitation and aeration device,the mixture can flow back to the aeration tank,extend the mud the residence time(SRT)and water retention time(HRT).The use of new rural life sewage decentralized treatment technology in the Zao Jia Town,Chen Liu part of the village of households decentralized domestic sewage treatment,and determine the stable operation condition and influence parameters ofthe engineering test and application research.The new type of rural life sewage decentralized treatment after the actual sewage treatment project construction and stable operation of the year,the sewage treatment effect is good,the sewage process reaction system with high anti hydraulic loading capacity and stable operation.The experimental results show that the process technology in the engineering operation process,can effectively remove COD,NH4+-N,SS and other pollutants,the average removal rate of pollutants reached 90%,87% and 91%.Domestic sewage through the sewage treatment system,COD,NH4+-N,SS are able to achieve the "urban sewage discharge standards"(GB18912-2002)first level B standard.Through the research on the engineering analysis,determined under the condition of normal temperature sewage treatment process under low flow state and denitrifying bacteria present in unsaturated conditions,the nitrogen removal effect is poor;but high reflux ratio,due to band to do,making denitrification of denitrifying bacteria are suppressed,and the nitrogen removal effect is poor.Said test data comparison,also considered the flow ratio,increased the cost of the investment and covers an area of,so make sure the reflux ratio of 1.5:1;with the hydraulic retention time longer,on COD removal effect is indeed an increase,but more than 12 hours,the effect is not very obvious,even will affect water quality stability,so make sure hydraulic retention time is not more than 12 hours;dissolved oxygen value should not only meet the organic pollution effective removal also should avoid high dissolved oxygen value inhibitory effect on denitrification.Through the test data show that determine the do value 3mg / L.