实际生活污水短程/全程硝化反硝化处理中试研究

常温条件下,用A/O生物脱氮工艺中试试验装置处理实际生活污水,控制好氧区低DO浓度(0.5 mg/L),实现了短程硝化反硝化反应,亚硝酸氮平均积累率可达85%或更高.研究了低DO短程硝化反硝化、低DO全程硝化反硝化和高DO全程硝化反硝化3种运行方式或状态在总氮去除率、耗氧量、污泥性能和反应机理上的差别.结果表明,短程硝化反硝化是生物脱氮的最优运行方式,它可有效提高系统脱氮率、降低运行费用.短程硝化反硝化过程中缺氧区和好氧区的pH值变化幅度较大;而全程硝化反硝化过程中,缺氧区pH值变化很小或基本不变化,好氧区pH值变化幅度较大.全程硝化和短程硝化的硝化速率相差不大,但短程反硝化速率和全程反硝化速率相比增加了15%.可以应用DO和pH在线控制A/O工艺硝化反应过程.

Short-Cut/Complete Nitrification and Denitrification in a Pilot-Scale Plant Treating Actual Domestic Wastewater

It is realized short-cut nitrification and denitrification in an A/O pilot-scale plant treating actual domestic wastewater controlling DO concentration(0.5(mg/L)) in low level at normal temperature,the average nitrite accumulation rate reached 85% or above.Three operational modes: low DO short-cut nitrification and denitrification(Mode 1),low DO complete nitrification and denitrification(Mode 2) and high DO complete nitrification and denitrification(Mode 3) were briefly compared,based on the nitrogen removal,operating cost,sludge characteristics and operational mechanism.Experimental results showed that the Mode1 is the best modes of biological nitrogen removal,in terms of improving nitrogen removal and reducing operating cost.The net pH change in aerobic zones and anoxic zones is high for Mode 1,but the net pH change in anoxic zones is very small for Mode 3.The nitrification rate is the smallest for Mode 2,and the nitrification rate for Mode 3 is little higher than that of Mode 1;the denitrification rate for Mode1 is larger than that of Mode 3 about 15%.It is feasible using DO and pH on-line sensors to control the nitrification process.