磁介质混凝沉淀工艺在污水处理厂深度除磷改造中的应用

Application of Magnetic Medium Coagulation and Sedimentation Process for WWTP Phosphorus Deep Removal Reconstruction

重庆市某污水处理厂现状规模为7.5万m^(3)/d,采用改良型氧化沟+滤布滤池处理工艺,出厂尾水达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。由于面临水体国控断面水质稳定达标的考核,工程在利用厂区有限用地的条件下,新增磁介质混凝沉淀工艺以提升处理效率。运行结果表明:污水处理厂整体出水效果提升,在90%覆盖率条件下,出水TP质量浓度为0.10 mg/L,SS质量浓度为4 mg/L,COD_(Cr)质量浓度为14 mg/L,BOD5质量浓度为2.3 mg/L,TN质量浓度为11.2 mg/L,氨氮质量浓度为0.30 mg/L,出水稳定达到准Ⅳ类标准。项目建设投资指标为468元/m^(3);运行药耗分别为:PAC(10%溶液)投加量为98 mg/L;PAM(阴离子)投加量为0.95 mg/L;磁粉的补充量为1.73 mg/L;电耗为0.021 kW·h/m^(3)。磁介质混凝沉淀工艺直接运行成本为0.111 0元/m^(3),主要成本为药剂,占比为85.41%。

A municipal wastewater treatment plant(WWTP)with a treatment capacity of 75000 m^(3)/d in Chongqing adopts the improved oxidation ditch and filter cloth filter treatment process.And the efluent stably meets the first class A criteria of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 189182002).Due to facing the assessment of achieving stable water quality standards at state-controlled water sections,the project adds the magnetic media coagulation and sedimentation process under the condition of using the limited zone in the WWTP to improve the treatment efficiency.The operation results show that the overall effluent effect of the WWTP is improved.Under the condition of 90%coverage,the effluent TP mass concentration is 0.10 mg/L,SS mass concentration is 4 mg/L,COD_(Cr) mass concentration is 14 mg/L,BOD_(5) mass concentration is 2.3 mg/L,TN mass concentration is 11.2 mg/L,and ammonia nitrogen mass concentration is 0.30 mg/L,which stably meets the requirement of quasi class IV water quality discharge standard.The investment indicator for project is 468 yuan/m^(3).The operational chemical consumption is as follows:PAC(10%solution)dosage is 98 mg/L,PAM(anionic)dosage is 0.95 mg/L,and the magnetic coagulation dosage is 1.73 mg/L.The electricity consumption is 0.021 kW·h/m^(3).The direct operating cost of the magnetic medium coagulation and sedimentation process is 0.1110 yuan/m^(3),with the main cost being chemical agent,accounting for 85.41%.