氨氮对A/O^2 MBBR处理垃圾焚烧渗沥液厌氧出水的影响

Effect of ammonia nitrogen on treatment of anaerobic effluent of leachate from MSW incineration plant by A/O^2 MBBR

采用缺氧/两级好氧MBBR处理垃圾焚烧渗沥液厌氧出水,研究高浓度氨氮对处理工艺脱氮效果的影响,采用变性梯度凝胶电泳技术分析各个处理单元在不同氨氮浓度下填料中微生物群落结构的变化。实验结果表明,在HRT=30 h和硝化液回流比300%条件下,当进水氨氮浓度达到700 mg·L-1,氨氮的转化率和总氮的去除率分别从99%和80%下降到50%,高浓度氨氮对硝化细菌产生了毒性作用;当进水氨氮浓度降低至500 mg·L-1,氨氮的转化率和总氮的去除率分别恢复到90%和70%,氨氮对硝化细菌的毒性作用是可逆的。反硝化细菌较硝化细菌对高浓度氨氮有较强的耐受能力。微生物群落结构没有发生明显变化,氨氮对微生物的毒性表现在对其生物活性的抑制。

An anoxic / two-stage aerobic moving bed biofilm reactor（ MBBR） was used to treat the anaerobic effluent comprising the leachate from an MSW incineration plant. The effect of a high ammonia-nitrogen concentration on the nitrification process was investigated. The changes in the microbial community structure of each reactor were analyzed by denaturing gradient gel electrophoresis（ DGGE）. Using an hydraulic retention time（ HRT） of 30 h and internal recycle ratio of 300%,the COD,NH_4^＋-N,and TN removal efficiencies were found to be respectively around 80%,99%,and 80%. When the influent NH_4^＋-N concentration increased to 700 mg·L- 1,the NH_4^＋-N and TN removal efficiency decreased to 50%. However,the NH_4^＋-N and TN removal efficiency returned to around 90% and 70% when the influent NH_4~＋-N concentration declined to 500 mg·L- 1. The inhibitory effect of NH_4^＋-N on the microorganisms was reversible. There were no significant changes in the microbial community structure. The reduction of the NH_4^＋-N removal efficiency under a high NH_4^＋-N concentration was due to a decrease in the bioactivity of the microorganisms.