回流比对悬挂链曝气式接触氧化工艺的影响

Influence of Internal Recirculation Ratio on a Contact Oxidation Process with Suspended Chain Aerator

采用悬挂链曝气式接触氧化工艺在不同回流比下处理城市河道污水,应用磷脂法、TTC-脱氢酶活性法和MPN法研究了载体表面生物膜特性,考察了回流比对生物膜特性和水质净化效果的影响.结果表明：在100%~300%之间,回流比对好氧区内生物膜量和生物活性影响不大,而回流比越大,缺氧区内生物膜量越多,NH＋4-N和TN的去除效果越好;回流比大于200%后,对缺氧区生物膜量及水质净化效果的影响减弱;最佳回流比为200%,对COD、NH＋4-N、TN和TP的平均去除率分别为78.0%、80.46%、66.4%和56.5%,出水水质达到《城镇污水处理厂污染物排放标准》（GB 18918—2002）一级标准B标准.

A contact oxidation process with suspended chain aerator was applied to treating the wastewater of urban rivers to study the superficial biofilm characteristics by the deter- mining methods of phospholipid, dehydrogenase activity and MPN and influence on biofilm characteristics and water quality decontamination under different internal reeirculation rati- os. The results showed that the internal recirculation ratio weakly influenced biomass and microbial activity in the aerobic zone between 100% and 300%. The greater the internal recirculation ratio was,the more biomass in the anoxic zone was and the better efficiency on removal of NH4 ＋ -N and TN were. When the internal recirculation ratio was greater than 200% ,influence of the internal recirculation ratio on biomass in the anoxic zone and effi- ciency of wastewater removal lowered. Average removal rates of effluent of COD ,NH4＋-N, TN and TP was 78.0% ,80.46% ,66.4% and 56.5% ,respectively,reaching B standard of discharge standard of pollutants for municipal wastewater treatment plant （GB 18918-- 2002） with the best internal recirculation ratio of 200%.