Technological Design On Project Construction Of QL Wastewater Treatment Plant In Heilongjiang Province

In the paper, the process design of first-stage project of Hejiagou Qunli wastewater treatment plant was studied. Through investigating the current situation of urban drainage in Hejiagou, we found that large urban sewage was discharged into the river, causing serious water pollution in the Songhua River. To improve the entire urban landscape and the water environment of Hejiagou upstream, it is necessary to build the Harbin Qunli wastewater treatment plant. At the same time, water reuse treatment plant is built to meet the application of water reuse system.By determining the overall program of wastewater collection, the dilution factor of Hejiagou was determined to be 1. 20. The demonstration results of drainage in the downstream urban section of Hejiagou showed that in 2010, the per capita water consumption integrated living standard 235L/person?d, industrial water consumption output value of per ten-thousand 16m3/ten-thousand, the predicted population in downtown section of Hejiagou is 296 thousands, the total output value of industry is 35. 15 billion RMB, the total amount of the calculated predicted drainage 210, 000 m3/d, water reuse 50, 000 m3/d. According to "Municipal Wastewater Treatment Plant Pollutant Emission Standards"(GB18918-2002), the effluent quality was designed to reach the B standard of the first level which is: SS:≤20 mg/L, BOD5:≤20 mg/L, CODCr: ≤60mg/L, NH4~N: ≤15 mg/L. Reuse water effluent quality should reach "Miscellaneous Domestic Water Quality Standards"(CJ25. 1-89), SS(mg/L)≤20, BOD5(mg/L)≤10, CODcr(mg/L)≤50, cloud degree(NTU) ≤10, ammonia(mg/L)≤20.Compare the advantages and disadvantages of A/O process and ICEAS process, ICEAS process had better performance in project investment, operating costs and environmental impact than A/O process, so the secondary treatment process of this project was recommended to use ICEAS. Reusing water treatment system adopts flocculation and D-filter technology. Sludge treatment system is employed dewatering process. Chlorine disinfection was chosen.The process of wastewater treatment is coarse screen—wastewater pumping station—fine rack—rotational flow grit chamber—ICEAS—disinfection tank—secondary pump station—Hejiagou. The design elevation was controlled in the range of 119. 0m~117.0m. During the design of screening, pump station and grit chamber, parameters selected and sizes designed were all according to relative regulations, standards and specifications. ICEAS system was divided into 4 groups, each group had 10 pools with 14 h HRT and 28 days sludge age, the daily sludge volume was 2, 667 m3/d. To ensure reasonable and safe operation of wastewater treatment plant, specific design for a special environmental protection, fire protection, safety and health and energy efficiency were conducted.Construction and operation of wastewater treatment plant will cause impact on the surrounding environment. According to the environmental impact assessment, during the construction and operation periods, the impact of the project on surface water, air and noise environment are under control, the project is feasible. By taking measures to solid waste disposal, solid waste disposal rate was 100%. The impact of solid waste on the environment is reduced to a minimum.