高出水标准下的再生水厂COD深度处理工艺比选

Comparison and Selection of Advanced Treatment Process for COD Removal from Reclaimed Water Plants with High Effluent Quality

北京市某再生水厂设计规模为8×10^4m^3/d,出水水质执行北京市地方标准《城镇污水处理厂水污染物排放标准》(DB 11/890—2012)A标准。该厂采用多段进水A^2O+MBR工艺作为主处理工艺,由于其出水COD很难稳定达到京标A标准的要求(COD≤20 mg/L),需增加COD深度处理单元。对目前可选择的深度处理工艺——臭氧催化氧化、脉冲炭吸附、下向流炭吸附及活性焦吸附工艺就占地面积、投资、运行成本及工艺的实际应用情况进行了比较。结果表明,臭氧催化氧化工艺占地面积最小,脉冲炭吸附和下向流炭吸附工艺初期投资较低,活性焦吸附及下向流炭吸附工艺运行成本更低。臭氧催化氧化、脉冲炭吸附、活性焦吸附工艺均有实际应用案例。综合考虑,最终确定脉冲炭吸附和活性焦吸附工艺是现阶段较好的COD深度处理把关工艺。

The effluent of a reclaimed water plant in Beijing,with a design scale of 8×10^4 m^3/d,implemented class A standard of Beijing local standard Discharge Standard of Water Pollutants for Municipal Wastewater Treatment Plants(DB 11/890-2012)(Beijing standard A).It was proposed to adopt multi-stage water inlet A^2O+MBR process.Because it was difficult for the effluent COD to stably meet the requirements of the Beijing standard A(COD≤20 mg/L),advanced COD removal processing unit ought to be added.The theoretically feasible methods,such as the ozone catalytic oxidation,the pulsed carbon adsorption tank,the down-flow carbon adsorption tank and the activated coke adsorption bed process,were compared in terms of land occupation,investment,operating cost and practical application of the process.The results showed that ozone catalytic oxidation covers the smallest area.The initial investment of the pulsed carbon adsorption tank and the down-flow carbon adsorption tank was lower,and the operating cost of the activated coke adsorption bed and the down-flow carbon adsorption tank was lower.The ozone catalytic oxidation,the pulsed carbon adsorption tank,the active coke adsorption bed had practical application cases of the wastewater plant.Considering the above factors,it was concluded that the processes of pulsed carbon adsorption and activated coke adsorption were the better processes for COD removing advanced treatment at present.