膜生物反应器处理晚期垃圾渗滤液亚硝化性能及其抑制动力学分析

采用连续流MBR反应器处理晚期垃圾渗滤液,考察其亚硝化性能;并探讨底物、产物和毒性物质对亚硝化性能的抑制及其动力学特性.结果表明,在进水NH₄⁺-N浓度为(280±20) mg/L时,通过控制DO为0.5~1 mg/L,pH值为7.8~8.2和温度为(30±1)℃,成功启动MBR的亚硝化工艺,在第32d时, NO₂^--N积累率为84.27%;后逐步升高进水负荷,并提高DO至2~3 mg/L,逐渐实现MBR系统中以晚期垃圾渗滤液原液为进水的亚硝化,在第112d时,系统出水NO₂^--N浓度为889 mg/L, NO₂^--N积累率为97.23%.底物、产物和毒性物质的抑制实验表明,毒性物质对微生物的抑制作用强于底物和产物;当毒性物质浓度(以COD计)为1600.2 mg/L时,氨氧化速率下降了22.15%,而相应条件下若以FA为单因子抑制时,氨氧化速率下降了4.74%~6.49%,若以FNA为单因子抑制时,氨氧化速率相比下降了14.46%~15.86%.分别采用Haldane底物抑制模型、Aiba产物抑制模型以及修正后的毒性物质抑制模型对实验数据进行非线性拟合,相关系数R²分别为0.9821、0.9961和0.9924,并得到底物、产物和毒性物质的抑制动力学模型.

Performance of nitritation process in membrane bioreactor for old landfill leachate and analysis of inhibition kinetics

The performance of nitritation were investigated in continuous flow MBR fed with old landfill leachate, the inhibition of substrate, product and toxicant on nitritation process and the inhibition kinetics were analyzed. The results show that:the nitritation process was started up in MBR which controlled the NH₄⁺-N concentration of inflow was (280±20) mg/L, the DO was 0.5~1.0 mg/L, pH was 7.8~8.2 and temperature was (30±1)℃; and at 32d, the nitrite accumulation rate was 84.27%. Influent load was increase gradually and improved the DO to 2~3 mg/L in the next period, nitritation process was realized gradually in MBR system which the inflow was the old landfill leachate completely, the ρ (NO₂^--N) of effluent from system was 889 mg/L and the nitrite accumulation rate was 97.23% at 112d. The inhibition experiments of substrate, product and toxicant showed that, the inhibition of toxicant surpass substrate and product, when the concentration of toxicant (calculated by COD) was 1600.2 mg/L, the ammonia oxidation rate declined by 22.15%, and if inhibition factor was FA only in corresponding conditions, ammonia oxidation rate decreased by 4.74%~6.49%, and if inhibition factor was FNA only in corresponding conditions, ammonia oxidation rate decreased by 14.46%~15.86%. Haldane model, Aiba model and the revised toxicant inhibiting model were adopted for nonlinear fitting on the experimental data respectively, the correlation coefficient R² were 0.9821, 0.9961 and 0.9924 respectively, and the inhibition kinetics models of substrate, product and toxicant were obtained.