快速启动厌氧氨氧化用于老龄垃圾渗滤液脱氮及其机理分析

基于短程硝化处理后的老龄垃圾渗滤液，含有大量难降解有机污染物，且氨氮和化学需氧量浓度高，C/N比低等特点。本研究以厌氧硝化污泥作为接种污泥，采用升流式厌氧污泥床反应器(UASB)，快速启动厌氧氨氧化反应，对其进行深度脱氮。探究启动厌氧氨氧化反应的最佳条件和脱氮性能，根据污泥形貌特征和微生物群落结构的变化，阐明厌氧氨氧化的作用机理。结果表明，厌氧氨氧化快速启动最佳条件：温度为(30±1) ℃、初始pH为7.5、NO₂^?/NH₄⁺为1.25~1.50、无外加碳源和MLSS为4 200 mg·L^?1。历经60 d后，厌氧氨氧化成功启动，进水TN容积负荷最高为0.45 kg·(m³·d)^?1，TN容积负荷去除速率最高为0.36 kg·(m³·d)^-1，NH₄⁺-N、NO₂^?-N和TN去除率超过80%。同时，UASB运行至第60天时，接种污泥形貌呈现花椰菜结构，微生物群落多样性减少，Planctomycetes门为优势菌群，其丰度为44.4%。Candidatus Brocdia属为第一优势菌属，其丰度为42.8%，证实厌氧氨氧化快速启动成功，AnAOB利用NO₂^?-N为电子受体，以NH₄⁺-N为电子供体实现深度脱氮。综上所述，厌氧氨氧化的快速启动可为短程硝化处理后的老龄垃圾渗滤液深度脱氮提供参考。

Nitrogen removal from mature landfill leachate and its mechanism by using fast start-up of anaerobic ammonia oxidation

In this study, anaerobic nitrification sludge was used as the inoculated sludge, and the upflow anaerobic sludge bed reactor (UASB) was used to perform the fast start-up of anaerobic ammonia oxidation (Anammox) to further remove nitrogen. Based on the characteristics of mature landfill leachate after short-cut nitrification treatment which contains a large number of refractory organic pollutants, high ammonia nitrogen concentration and chemical oxygen demand, and low C/N ratio. The optimal conditions and denitrification performance for Anammox reaction were explored, and the mechanism of Anammox was also elucidated according to the changes of sludge morphology and microbial community structure. The results showed that the optimal condition for fast start-up of the Anammox process was (30±1) ℃, initial pH=7.5, NO2?/NH4+=1.25~1.50, without external carbon source and MLSS=4 200 mg·L?1, respectively. After 60 days, the successful fast start-up of Anammox occurred, the removal rates of NH4+-N, NO2?-N and TN exceeded 80% when the inlet TN volume load was 0.45 kg·(m3·d)?1 and the TN volume load removal rate was 0.36 kg·(m3·d)-1. The result of scanning electron microscopy (SEM) revealed that the morphology of inoculated sludge exhibited cauliflower structure after 60 days operation of UASB process. Simultaneously, the result of 16S rRNA high-throughput sequencing indicated that the diversity of microbial community decreased after start-up. Planctomycetes phylum was the dominant bacterial community, with an abundance of 44.4%, and Candidatus Brocdia was the dominant genus, with an abundance of 42.8%. Both results of SEM and 16S rRNA confirmed that the fast start-up of Anammox was successful. AnAOB uses NO2?-N as the electron acceptor and NH4+-N as the electron donor for deep denitrification. In conclusion, the fast start-up of process of Anammox provides a reference for the deep nitrogen removal of mature landfill leachate after short-cut nitrification.