间歇曝气SBR处理垃圾渗滤液的脱氮性能

Nitrogen removal performance of an intermittent aeration sequencing batch reactor for treatment of landfill leachate

采用两级串联间歇曝气序批式反应器(intermittent aeration sequencing batch reactor,IASBR)处理高氨氮低碳氮比的垃圾渗滤液,研究在控温(25±2)℃,进水碳氮比(COD/TN)为3.0条件下的脱氮性能。进水氨氮(NH_4^+-N)和总氮(TN)浓度分别为(1 100±70)mg·L^(-1)和(1 520±65)mg·L^(-1),1级和2级IASBR的水力停留时间(HRT)分别为5 d和4 d。运行结果表明,经1级IASBR处理后,出水TN浓度降低至约250 mg·L^(-1),其中以有机氮(TON)为主,NH_4^+-N浓度约25 mg·L^(-1);经2级IASBR处理后,出水TN和NH_4^+-N浓度分别稳定在40 mg·L^(-1)和20 mg·L^(-1)以下,TON去除率高达90%以上。两级串联IASBR组合工艺表现出良好的深度脱氮性能,出水TN浓度稳定达到《生活垃圾填埋场污染控制标准》(GB16889-2008)中TN≤40 mg·L^(-1)的排放标准;同时,1级IASBR出水COD浓度高达1 150 mg·L^(-1),经过2级IASBR处理后出水COD降至约770 mg·L^(-1)。

Two-stage intermittent-aeration sequencing batch reactors（ IASBR） were applied to treat landfill leachate characterized by high ammonium concentration but low C/N ratio. Nitrogen removal performance was studied at the water temperature of（ 25 ± 2） ℃ and influent COD/TN ratio of 3. 0. The influent NH4~＋-N and TN concentrations were（ 1 100 ± 70 and 1 520 ± 65） mg·L^-1,respectively. The hydraulic retention time was five and four days,in the first and second stage,respectively. The results showed that the effluent TN concentration in the first IASBR decreased to about 250 mg·L^-1,in which organic nitrogen was dominant,while the NH4~＋-N concentration was only 25 mg·L^-1. After treatment by the secondary IASBR,the effluent TN and NH4~＋-N concentrations were greatly decreased（ 40 and 20 mg·L^-1,respectively） and more than 90% of the organic nitrogen was removed. The two-stage IASBR showed excellent performance on nitrogen removal and the effluent TN met the emission requirement of GB16889-2008（ 40 mg·L^-1）. Up to 1 150 mg·L^-1 of COD remained in the effluent of the first IASBR,but was down to 770 mg·L^-1after treatment in the second IASBR.