利用好氧颗粒污泥持续增殖启动高性能亚硝化反应器

Start-up of a High Performance Nitrosation Reactor Through Continuous Growth of Aerobic Granular Sludge

为了考察亚硝化颗粒污泥(NGS)的持续增殖能力,向柱状序批式反应器(SBR)内接种极少量种污泥,在130 d内,将氨氮容积负荷(NLR)从0.74 kg·(m^3·d)^(-1)提高到6.66 kg·(m^3·d)^(-1),成功使反应器内污泥浓度(MLSS)从0.1 g·L^(-1)增长至11.8 g·L^(-1),对应的亚硝态氮累积负荷从0.4 kg·(m^3·d)^(-1)升至4.9 kg·(m^3·d)^(-1).当NLR低于4.44 kg·(m^3·d)^(-1)时,反应器内粒径<200μm的污泥数量明显增多,颗粒平均粒径大幅减小.当NLR继续提高时,颗粒平均粒径的增长过程遵循修正的Logistic模型,其比增长速率k值约为0.022 9 d-1.在运行期间,较高的游离氨(FA)和游离亚硝酸(FNA)浓度能够对亚硝酸盐氧化菌(NOB)起到联合抑制作用,这使得出水中亚硝态氮累积率(NAR)始终高于80%.上述实验结果将为工业化高效NGS反应器的启动操作提供重要参考.

In order to examine the continuous growth capacity of the nitrosation granular sludge（ NGS）,the sludge was inoculated to start up the columnar sequencing batch reactor（ SBR）. During 130 d,the concentration of mixed liquor suspended solids（ MLSS） in SBR increased from 0. 1 g·L^-1to 11. 8 g·L^-1,corresponding to the nitrite-nitrogen accumulation rate of 0. 4-4. 9 kg·（ m^3·d）^-1,promoted by a higher ammonia-nitrogen loading rate（ NLR） from 0. 74 kg·（ m^3·d）^-1to 6. 66 kg·（ m^3·d）^-1in the influent. Because of the obvious increase in small granules（ size 200 μm）,the mean average diameter of NGS decreased significantly at NLR 4. 44kg·（ m^3·d）^-1. At higher NLR values,the growth of the mean average diameter of NGS could be fitted well using a modified logistic model. The specific growth rate of the k value was 0. 022 9 d^-1. In addition,the combined inhibition of nitrite oxidizing bacteria（ NOB） was expected at relatively high concentrations of both free ammonia（ FA） and free nitrite acid（ FNA）; thus,the nitrite accumulation ratio（ NAR） in the effluent was always higher than 80%. These results provide a feasible approach to start up a highperformance NGS reactor at the industrial-scale.