缺氧／好氧和协同控制DO／HRT工艺对亚硝化的影响比较

摘要

为比较协同控制DO／HRT和缺氧／好氧两种运行方式对亚硝化的影响，在常温（18～22℃）下，采用两组2级连续搅拌反应器（ CSTR），1＃采取协同控制DO／HRT的启动和运行方式，2＃采取缺氧／好氧的方式，分别比较两种方式在亚硝化的启动时间、稳定运行效果、曝气能耗、对进水NH4＋－N质量浓度下降的适应性以及污泥沉降性能上的差异．结果表明：1＃、2＃分别用了26和41 d实现了亚硝化；在以原水经AO除磷出水为进水时（ NH4＋－N质量浓度35～43 mg／L），两种运行方式亚硝化效果均较好，但缺氧／好氧的运行方式节省了约20％的曝气能耗．当进水NH4＋－N质量浓度由43 mg／L下降到27 mg／L时，1＃亚硝化失稳，最终亚硝化率下降到67．39％，而2＃亚硝化较稳定，亚硝化率保持在88％以上；1＃和2＃在整个过程中污泥沉降性能良好．利用协同控制DO／HRT的方式启动亚硝化，随后转变为缺氧／好氧运行，有助于亚硝化的快速启动和稳定运行，并能节省曝气能耗．%To compare the effect of two different operational modes on partial nitrification ( PN ), two⁃stage continuous stirred⁃tank reactors (CSTR) 1#(anoxic⁃oxic) and 2#(controlling DO and HRT) were constructed and operated at room temperature (18-22℃). Start⁃up time, stability, aeration consumption, sludge settling ability, as well as the adaptability to the decreasing of ammonia nitrogen concentration were investigated. PN in 1#and 2#were accomplished in 26 d and 41 d, respectively. When the effluent of an anaerobic/oxic ( A/O) process for phosphorous removing (containing ammonia nitrogen 35-43 mg/L) was used as influent, PN was stable both under 1# and 2#condition, however, aeration consumption could be reduced by about 20% in 2#. When the ammonia nitrogen decreasing from 43 to 27 mg/L, PN in 1# would be unstable and the rates of PN decreased to 67.39%. For comparison, PN in 2#could be maintained stable with an ammonia removal rate of >88%. Settleability of sludge was good both in 1#and 2#. Rapid start⁃up could be achieved through controlling DO and HRT, and a stable and efficient PN could be maintained through anoxic⁃oxic.