【正文】 fective volume 3925 m3 / h.(7)Orbal oxidation ditch Aubert oxidation ditch, it is elliptical reinforced concrete pool, divided into pool is divided into three annular channel, turn sewage into the outer channel, the channel and inside the channel, and finally by the center of the island and into the sedimentation tank with water flow 1250m3 / h, every seat effective volume 11000m3, the mixture concentration g / l, the design depth of , HRT and oxidation ditch is a core part of the entire processing system, its main function is to make the cultivation of domesticated activated sludge degradation, adsorption, aggregation of organic matter, and through the action of bacteria so that the suspended particles and dissolved particles tend to precipitate, resorted to water The organic content is seat is installed oxidation ditch aeration plate spinning disc 10 sets, outside the channel dissolved oxygen control in / l, in the meantime oxidation, nitrification and intermediate channel and an outer channel dissolved oxygen controlled at 1mg / l and 2mg / l, of organic matter in sewage further oxidation, to ensure the organic content of the effluent to meet the design requirements.(8)sedimentation Water will be discharged into the oxidation ditch treatment after sedimentation tanks, sedimentation tanks using radial flow sedimentation tank, water center, surrounded by water, the diameter D = 38m, a total of with wells located two blocks, through contact with sewage into the pool after seat settling ponds located around the drive fullbridge scraping suction machine, sedimentation tank sludge and sludge pumping station to flow 1813m3 / h, maximum surface load m3 / , singlecell pool depth of 4m, the residence time of .(9)contact tank To ensure the cleanliness of the water due to the standards required to be disinfected so, it set up contact with the cell holder 1: 1813 m3 / h flow rate, contact time 30min, effective contact volume 1056 m3, the effective depth of project uses chlorine dioxide disinfection, contact tank responsible for wastewater effluent dosing point sewage pond in the front reflux 1813 m3 / h, the average amount of chlorine 8 mg / l, a single effective yield chlorine / h.(10)reflux and sludge pumping station As part of the water will precipitate some sludge, so the return sludge pump submersible pump, to enhance the use of sludge submersible centrifugal pumps, construction simple and pact sludge volume 1250 m3 / h, the sludge moisture content %.(11)between chlorination This project uses chlorine dioxide disinfection, contact tank responsible for wastewater effluent dosing point sewage pond in the front reflux 1813 m3 / h, the average amount of chlorine 8 mg / l, a single effective yield chlorine / , the significance of the sewage treatment With the development of urban water shortages increasing pressure to pursue the root causes of urban water crisis, it is increasingly recognized that munity water cycle beyond the natural cycle of water can carry a , only full respect for the natural movement of water, the rational use of water resources, making water recycling upstream region does not affect the function of water downstream waters, without prejudice to the objective laws of social cycle natural circulation, thereby maintaining or restoring good water environment and the watershed of the city, The effective way is the sustainable use of water resources which requires us from “wateruser” into open water unidirectional mode is “sparingly wateruserrecycled water” feedback circulation processes, improve water use this major shift patterns of water use and enhance wastewater reuse is the the advancement of science and technology, urban sewage is no longer a waste, but a valuable is a resource, it is necessary to maximize the urban sewage recycling rate, one can reduce pollutant emissions, and second, to save the limited water Division of Water Resources Deputy Director Xiaoice from Tsinghua Speaking on the university and China Water Network39。.Site is located 5 km southeast of the city of Xuanhua District, covering acres。Survey Xuanhua District sewage treatment plant Survey Time: 2015221 Survey Location: Zhangjiakou, Hebei Xuanhua District Wastewater Treatment Plant Science sewage treatment is an urgent requirement of economic and social development, but also practical problems of urban construction process must recent years, the county government attaches great importance to urban environmental remediation work, will this work for the improvement of urban living environment, promoting urban and rural development, an important starting point to build a harmonious the past few years, Xuanhua District sewage treatment has done a lot of work and achieved some District sewage treatment plant and sewer network project in 2001 by the Provincial