游离氨对老龄填埋污泥脱水液短程硝化的影响

Effect of FA on Shortcut Nitrification of Dewatering Filtrates in Aged Landfill Sludge

针对老龄填埋污泥高氨氮低碳氮比(C/N)的特点,采用两级AO-MBR工艺探讨短程硝化处理实际老龄填埋污泥脱水液的可行性,在获得稳定的污染物去除效果的前提下,重点考察游离氨(FA)对短程硝化稳定性的影响。结果表明,亚硝酸盐氮(NO_(2)^(-)-N)积累率(N_(NAR))与FA浓度呈二次相关,在较高FA浓度下,一级硝化池(O1)池的N_(NAR)超过50.0%,最高达76.9%,实现了短程硝化,微生物菌群结构信息表明O1池中氨氮氧化菌(AOB)的物种丰度远高于二级硝化池(O2),且O1池中AOB的物种丰度是NO2--N氧化菌(NOB)的10倍以上;FA对AOB的抑制作用符合底物抑制动力学Haldane模型,拟合得到,AOB的最大比增殖速率(μmax)为0.34 g N/(g VSS·d),毒性抑制常数(K_(i))为143.4 mg/L,半饱和常数(K_(s))为38.3 mg/L,综合考虑进水的波动性与实际生产应用,系统FA质量浓度控制在40~80 mg/L为宜。研究结果为未来老龄填埋污泥脱水液处理设施的设计和运行提供了参考。

In view of the characteristics of high ammonia nitrogen and low C/N of aged landfill sludge,the two-stage AO-MBR process is used to explore the feasibility of partial nitrification treatment of denatering filtrates of actual aged landfill sludge.On the premise of achieving stable pollutant removal efficiency,the focus is on investigating the impact of free ammonia(FA)on the stability of partial nitrification.The results showed that the nitrite nitrogen(NO_(2)^(-)-N)accumulation rate(N_(NAR))showed a quadratic correlation with FA concentration.At higher FA concentration,the N_(NAR)in the primary nitrification tank(O1)exceeded 50.0%,with a maximum of 76.9%,achieving partial nitrification.The microbial community structure information indicated that the species abundance of ammonia nitrogen oxidizing bacteria(AOB)in the O1 tank was much higher than that in the secondary nitrification tank(O2),and the species abundance of AOB in the O1 tank was more than 10 times that of NO-2-N oxidizing bacteria(NOB).The inhibitory effect of FA on AOB conforms to the Haldane model of substrate inhibition kinetics,and the maximum specific proliferation rate of AOBμmax was 0.34 g N/(g VSS·d),the toxicity inhibition constant(K_(i))was 143.4 mg/L,and the semi saturation constant(K_(s))was 38.3 mg/L.Taking into account the fluctuation of influent water and practical production applications,it is advisable to control the concentration of FA in the system from 40 mg/L to 80 mg/L.This paper provides a reference for the design and operation of future aged landfill sludge dewatering liquid treatment facilities.