Researching And Designing On CiXian Sewage Treatment Plant Upgrading Project

With the development of domestic and foreign sewage treatment technology and the output water quality for Urban sewage treatment plant elevating, upgrading of many domestic sewage treatment plants is imminent.《Urban sewage treatment plant pollutant discharge standard》(GB18918-2002) issued by the SEPA and the AQSIQ in2002, its explicit requirements A and B level in first grade standard for effluent quality. The SEPA modified the standards of2002in2006, it clearly defined:It must be performed A level in first grade standard when sewage treatment plant effluent introduced into the dilution capacity of smaller rivers and lakes as water and general townscape reuse water and other purposes.Cixian sewage treatment plant was established in2010.10, using of three oxidation ditch process, treatment of water is30,000cubic meter/day. Although it eased the deterioration of water environment within the city initially, but because of the low standards of the original design.The original design for output water was B in first grade standard, has been urable to meet the requirements of green and landscape water, so development zone upgrades to effluent complying with the A level.Processing object of this project is B standard effluent, determining subjoin depth treatment systems based on the biological treatment biological treatment by the analysis and comparison, recommended depth treatment process using biological aerated filter (BAF) process. The specific technology is the DN biological filter+C/N biological aerated filter, used to removal pollutants as TN、TP、COD、BOD、SS Etc. of sewage. BAF combines the multiple purification filtration, adsorption and biological metabolism, it has the characteristics of small volume, small footprint, the higher efficiency, the better water quality, simple process and eliminating the secondary sedimentation tank.Combined with the inflow and output water quality of depth processing systems, calculated for each structure, proposed recommendatory parameters, and analyzed the economic efficiency、environmental benefits and social benefits.In this paper, done to explore and elaborate form the theory of the upgrading of Cixian sewage treatment plant, providing some reference for this engineering design and construction.