Abstract: Both “two-stage upflow anaerobic sludge blanket(UASB)+anoxic/oxic (A/O)” system and “one stage UASB+A/O” system were successively introduced to treat a leachate containing relatively low concentration of organics and high concentration of ammonia from a mature landfill site. The “two-stage UASB+A/O” system was used firstly. The denitrification of the return effluent was carried out in the first stage UASB (UASB1). The nitrification took place in the A/O reactor. The results showed that most biodegradable organic matter was removed in the UASB1, so “one stage UASB+A/O” system was used in the second phase experiment. The NH+4-N loading rate of A/O reactor and operation temperature were 0. 28—0. 60 kg NH+4-N·m-3·d-1 and 17—29℃, respectively. The COD removal efficiency and the final effluent COD were 50%—70%, 1000—1500 mg·L-1, respectively. Short-cut nitrification with 90%—99% of nitrite accumulation efficiency took place in the system. The NH+4-N removal efficiency varied between 90% and 100%. When NH+4-N loading rate was less than 0. 45 kg NH+4-N·m-3·d-1, the NH+4-N removal efficiency was more than 98%, and effluent NH+4-N was below 15 mg·L-1. When the ratio of the feed COD to feed NH+4-N concentrations was 2—3, the total inorganic nitrogen (TIN) removal efficiency was 70%—80%. The sludge samples from A/O reactor were analyzed by using fluoresence in situ hybridization(FISH). The FISH analysis showed that ammonia oxidation bacteria (AOB) were 4% of the eubacteria, meanwhile nitrite oxidation bacteria (NOB) were less than 0. 2% of the eubacteria.

摘要： 试验用水为典型的晚期城市生活垃圾渗滤液。第一阶段试验采用“两级UASB+A/O”系统，在一级UASB中进行回流处理水反硝化，二级UASB进行产甲烷反应，A/O反应器进行NH4+-N硝化反应。第一阶段研究表明可生化有机物在一级UASB几乎全部降解，所以第二阶段试验取消第二级UASB形成“一级UASB+A/O”系统。系统的有机物去除率＝50~70％，系统出水COD＝1000~1500 mg•L-1。当运行温度为17~29℃时，实现了稳定的NO2--N累积率为90~99％的短程硝化。试验期间 NH4+-N负荷（ALR）=0.28~0.60 kgNH4+-N•m-3•d-1，NH4+-N硝化率=90~100%。当ALR <0.45 kgNH4+-N•m-3•d-1，硝化率>98％，出水NH4+-N<15mg•L-1。在进水COD/NH4+-N＝2~3时，无机氮TIN去除率＝70~80％。采用荧光原位杂交技术（FISH）对活性污泥进行检测，结果表明，A/O工艺活性污泥中的NH4+-N氧化菌（AOB）为细菌总数的4％左右，NO2--N 氧化菌（NOB）数量不足细菌总量的0.2％。