DO对低C/N比污水生物亚硝化的影响分析

采用活性污泥法SBR工艺,考察DO对亚硝化的影响。首先进行195 d的连续培养试验,得出亚硝化系统DO保持在0.2 mg/L~0.6 mg/L的范围之内,可使得到有效降解且出水亚硝化率达50%~90%;然后研究系统周期内DO的变化规律,可以考虑以12 h为一个亚硝化反应周期,若延长反应时间至16 h,将使反应有向硝酸型硝化转移的趋势;最后通过烧杯试验,得出随着系统DO浓度的升高,氨氮降解率上升、亚硝化率下降,遵循DO与氨氮降解率和亚硝化率关系的数学模式。

Influence of DO on Nitrification of Municipal Wastewater with Low C/N Ratio

Through the test on activated sludge in SBR reactor,the influence of DO on nitrification is studied.First,through a 195d continuous test,to maintain the DO concentration of nitrifying system at a low level,if the DO is in range between 0.2 mg/l(start) ~0.6 mg/l(end) there will be high NH 4-N reduction and the nitrification ratio will reach 50~90%;Second,according to the regularity of DO in a cycle,12h as a react time is proper.If the react time of 16h is taken,it will be a traditional nitrification.At last,through bottle reactors,it can be concluded that when the DO concentration of system rise,NH 4-N the reduction ratio will rise too,but the nitrification ratio will drop,the NH 4-N reduces and the nitrification ratio can be calculated from a formula.