FNA处理絮体污泥恢复城市污水PN/A工艺短程硝化

Restoration of nitritation of the sewage partial nitritation/anammox(PN/A) proccess using free nitrous acid to treat flocculent sludge

为了探究游离亚硝酸(FNA)旁侧处理絮体污泥来恢复城市污水短程硝化/厌氧氨氧化一体化(PN/A)工艺的可行性,考察了不同浓度FNA对氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)活性的影响,探究了SBR反应器两次采用FNA处理絮体污泥的运行效果.结果表明:采用0.45mgHNO2-N/L的FNA处理能够抑制NOB活性,亚硝积累率(NAR)达88.8%,但投加后第8d开始NOB活性逐渐恢复.采用1.35mgHNO2-N/L的FNA处理能够显著抑制NOB活性,NAR达89.1%,与此同时AOB活性也受到抑制,氨氮转化率降低为6.8%.采用增大好/缺氧时间比即t好/t缺(由0.4~2.7)以及提高DO(由0.3~1.5mg/L)的方法能够恢复AOB活性,氨氮转化率达77.8%,在150d内NOB活性未恢复,NAR达98.1%.随着短程硝化的稳定实现,系统脱氮性能逐渐恢复,平均出水总无机氮(TIN)为8.2mg/L,平均TIN去除率为84.1%.因此,通过先用较高FNA处理絮体污泥同时抑制AOB与NOB,再采用增大t好/t缺并提高DO来恢复AOB活性的策略,能够实现PN/A工艺短程硝化的恢复.

In order to assess the feasibility of restoring sewage partial nitritation/anammox(PN/A)process using free nitrous acid(FNA)to treat flocculent sludge,the effect of different concentrations of FNA on the activities of ammonium oxidizing bacteria(AOB)and nitrite oxidizing bacteria(NOB)was studied.Besides,the variations of nutrient removal performance in the SBR reactor by twice FNA treatment were investigated.The results showed that NOB activity could be inhibited when the flocculent sludge treated by FNA of 0.45mgHNO2-N/L and the nitrite accumulation rate(NAR)reached 88.8%,but NOB activity recovered from the 8th day.While NOB activity could be significantly inhibited when the flocculent sludge treated by FNA of 1.35mgHNO2-N/L,and the NAR reached 89.1%.Meanwhile the activities of AOB was also inhibited,and NH4+-N conversion rate decreased to 6.8%.By enhancing the ratio of aerobic time to anoxic time(t好/t缺:from 0.4~2.7)and increasing dissolved oxygen(DO:from 0.2~1.5mg/L),the AOB activity recovered,and NH4+^-N conversion rate reached 77.8%.But the activities of NOB was not recovered within 150days,and the NAR achieved 98.1%.With the stable achievement of nitritation,the nitrogen removal performance of the system gradually restored,the average effluent total inorganic nitrogen(TIN)was 8.2mg/L,and the average TIN efficiency was 84.1%.Therefore,the strategy by first treating flocculent sludge with higher FNA to inhibite both AOB and NOB,then increasing t好/t缺and DO to restore AOB activity,could achieve the restoration of PN/A process.