改良型二段接触氧化工艺用于污水厂改扩建

Application of Improved Two-stage Contact Oxidation Process in a Wastewater Treatment Plant Upgrading

针对某城市污水厂原二段接触氧化池运行中存在的初沉池沉淀效果差、脱氮及除磷效率较低、氧化池底部积泥严重等问题,在工程改扩建设计中采用了强化脱氮除磷的改良型二段接触氧化池工艺。该工艺通过设置缺氧池并增加消化液回流系统、在二沉池前端设置化学除磷系统、在氧化池内增设排泥系统等措施,来提高脱氮除磷的效率。运行结果表明,在投加化学除磷药剂的条件下,改良型二段接触氧化池对COD、BOD5、氨氮、总氮、总磷的去除率分别可达80%、85%、90%、80%、85%,出水水质满足GB 18918—2002一级B标准。

According to the problems existing in the municipal sewage treatment plant of two-stage contact oxidation process, such as poor precipitation in primary sedimentation tank, low denitrification and phosphorus removal efficiency, and serious sludge accumulation in the oxidation tank, an improved two-stage contact oxidation tank for effective removal of nitrogen and phosphorus was proposed. The process improves the efficiency of nitrogen and phosphorus removal by transformation of the primary sedimentation tank into an anoxic tank and application of the digester return system, installation chemical phosphorus removal facilities at the front end of the second settling tank, and addition sludge removal facilities in the oxidation tank. The operation results indicated that the removal rates of COD, BODs, NH4^＋ -N, TN and TP could respectively reach 80% , 85% , 90% , 80% , 85% under the conditions of chemical phosphorus removal agent. The effluent quality could meet the first level B standard of GB 18918 - 2002.