缺氧/好氧和协同控制DO/HRT工艺对亚硝化的影响比较

Comparison of effects on partial nitrification between anoxic-oxic and controling DO /HRT process

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.

Abstract:

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.