分段进水两级A/O工艺对白酒废水的强化处理效果

Effects of Step Feed Two-Stage A/O Process on the Enhancement of Liquor Wastewater Treatment

为有效控制白酒废水中高质量浓度NH_4^+-N对A/O系统冲击引起的出水水质超标问题,分析比较单级A/O工艺和分段进水两级A/O工艺[进水时间(以min计)分配比为7∶3]对白酒废水的处理效果.结果表明:与单级A/O工艺相比,分段进水两级A/O工艺出水中ρ(NH_4^+-N)、ρ(NO_2^--N)、ρ(NO_3^--N)和ρ(COD_(Cr))均显著降低,其平均去除率分别提高了16.9%、43.2%、49.7%和8%.分段进水两级A/O工艺的二次进水能够为短程硝化反硝化的进行提供有效碳源和NH_4^+-N等,为NO_2^--N和NO_3^--N等去除提供了有利条件;同时,它通过促进对系统内碳源的利用以及NO_2^--N的去除,进一步降低了出水中ρ(COD_(Cr)).此外,分段进水两级A/O工艺通过降低NH_4^+-N和NO_2^--N等污染物质量浓度,也能有效减弱其对氨氧化菌和亚硝酸盐氧化菌等微生物的抑制作用,为后续好氧阶段含氮污染物的去除奠定基础.但是,分段进水两级A/O工艺对白酒废水中PO_4^(3-)的去除效果有限,这主要是因为第二阶段的NO_2^--N存在使反应系统处于缺氧环境,同时在碳源不充足的情况下,导致聚磷微生物释磷不充分,降低了第二好氧段的吸磷动力.研究显示,分段进水两级A/O工艺能够有效强化白酒废水中三态氮和COD_(Cr)的降解去除.

In order to prevent the shock load of high concentration of NH 4+-N on A/O system,the comparisons of single A/O process and step feed two-stage A/O process(the ratio of influent volume during the two feeds was 7∶3)on the treatment of liquor wastewater with high NH 4+-N were conducted.The concentration of NH 4+-N,NO 2--N,NO 3--N and COD Cr in the effluents was efficiently reduced by the step feed two-stage A/O process.The removal efficiencies were respectively enhanced by 16.9%,43.2%,49.7%and 8%comparing with that in single A/O process.The reasons could firstly attribute to the supplements of required carbon sources and NH 4+-N for the short-cut nitrification and denitrification in the secondary feed,which was beneficial to the removal of NO 2--N and NO 3--N.Meanwhile,the efficient utilization of carbon sources and the removal of NO 2--N also contributed to the reduction of COD Cr in the effluents.Moreover,the step feed two-stage A/O process could also relieve the inhibitory effects of NH 4+-N and NO 2--N on the microbial activities of ammoniA/Oxidizing bacteria and nitrite-oxidizing bacteria,which was superior to the further removal of NH 4+-N in aerobic process of the second A/O stage.However,the step feed two-stage A/O process had little effects on the removal of PO 4 3-.The accumulation of NO 2--N in the secondary A/O stage made the reactor into anoxic state.It would result in the inadequate release of phosphorus and then reduce the potential of phosphorus uptake by phosphorus-accumulating bacteria in oxic condition.The results indicated that the step feed two-stage A/O process could remarkably enhance the removal efficiency of typical pollutants(NH 4+-N,NO 2--N,NO 3--N and COD Cr)in liquor wastewater.