单级UASB-A/O组合工艺处理实际垃圾渗滤液

Single-stage UASB-A/O System for Treatment of Real Landfill Leachate

采用单级UASB-A/O组合工艺处理实际高氨氮渗滤液,在获得稳定有机物和氮同步去除的前提下,重点考察了通过控制游离氨(FA)和游离亚硝酸(FNA)快速实现A/O工艺短程硝化的可行性,同时分析了短程硝化影响因素.试验结果表明:在单级UASB反应器内发生高效的反硝化现象,实现了有机物和氮的同步深度去除,系统对COD和NH4+-N的去除率均在90%以上.室温条件下基于高FA和FNA对亚硝酸盐氧化菌(NOB)的协同抑制,A/O反应器内实现并维持了稳定的短程硝化,NO2--N累积率维持在89%～99%.抑制机理分析认为,FA对亚硝酸盐氧化还原酶或对起传递电子、移动质子作用的酶产生抑制.液相基质FNA通过主动扩散作用进入细胞膜,改变胞内pH值,从而影响了氧化磷酸化合成ATP所需的质子力.

Simultaneous removal of organic and nitrogen from landfill teachate with high level of nitrogen by using single-stage UASB-A/O system was investigated. On the basis of these, the feasibility of partial nitrification in A/O reactor through the inhibition of FA and FNA and the influence factors of partial nitrification were further studied in this work. The result showed that denitrifieation occurred in UASB reactor where COD and nitrogen were removed simultaneously and efficiently from landfill leaehate with the removal efficieneies of above 90%. Partial nitrification in A/O reactor was successfully achieved and maintained through the simultaneous inhibition by free ammonia and free nitrous acid at ambient temperature. The nitrite accumulation ratio reached 89% - 99%. Inhibitory mechanism of FA and FNA was summarized and described according to many reported literatures. It may be due to a direct inhibitory effect of FA on the nitrite oxidoreductase, or an enzyme involved in the electron transport or proton translocation. FNA in liquid phase diffused into cell membrane of microbial bacteria, resulting in the change of pH in the cell membrane, further affecting the proton force to meet the requirement of synthesizing ATP via oxidative phosphorylation.