The Preliminary Design Of Sewage Treatment Plant Project In The Town Of Xun County

With the national process of urbanization continues to accelerate, increasing demands of environmental protection, water pollution problems of small towns has become a matter of concern. The municipal sewage treatment plants are urban infrastructure projects which are play very important roles in improving the urban environment, improving people’s quality of life and promoting economic development in the region.The process design basis on the town of Xun County sewage treatment plant,according to the information provided, determine the design scale of sewage treatment plant, designed the quality of water, and the technology programs of sewage treatment, the layout and vertical layout of the sewage treatment plant as well as the plans and sections of the main structure in the plant are completed.The area of sewage treatment plant in the town of Xun County is determined as1.0 × 104 m 3 /d, its effluent water for sewage discharge is required by “discharge standard of pollutants for municpal wastewater treatment plant”(GB18918-2002) of class A. According to the sewage water quality and the discharge standard of wastewater treatment process, with comprehensive analysis and comparison, this design recommends the process of “Pretreatment + Modified Carrousel Oxidation Ditch + Reaction and Sedimentation Tank + Stainless Steel Filter + Contact Disinfection”. The process has the features of low investment, small occupied area,good effluent quality and so on. Sludge produced by sewage treatment process of sewage treatment plant are transported outward and landfilled after concentration and dehydration.The construction of the project is the need of economic development and environmental protection, it can effectively improve the regional environment. The corresponding mass of CODcr、BOD5、SS、NH3-N、TN、TP values are 1095.0、693.5、693.5、109.5(98.55)、109.5、14.6 t/a, realizing remarkable environmental benefits. After the project is completed, it can improve the investment environment,promote economic development and increase its visibility, so the social benefits areobvious. It is also a public good, it does not produce direct economic benefits, but indirect economic benefits.