ASBR联合SBBR工艺同步硝化反硝化处理垃圾渗滤液深度脱氮效能

为了提高垃圾渗滤液生化处理的TN去除率，采用厌氧序批式反应器（ASBR）串联序批式生物膜反应器（SBBR）处理化学需氧量（COD）为（5 700±500）mg/L、TN浓度为（210±50）mg/L的实际垃圾渗滤液。结果表明：ASBR的出水进入SBBR反应器进行深度脱氮，主要作用是调节后续SBBR进水的碳氮比（C/N），ASBR对渗滤液COD的去除率为90%。C/N是决定SBBR脱氮效率的关键，进水C/N调至4.8，在生物膜的作用下，SBBR仅通过厌氧搅拌和好氧阶段的同步硝化反硝化（SND）便可以实现对垃圾渗滤液的深度脱氮，出水TN浓度低于10 mg/L，周期运行时长也由第54天的24 h缩短至5.6 h。整个串联系统经过103 d的驯化和启动可以达到最佳的处理效果，出水COD、氨氮（NH₄ ⁺-N）、TN浓度分别为（380±10）、（1.0±0.5）、（5±5）mg/L，去除率分别达到93%、99%和95%。通过高通量测序分析可知，系统中变形菌门（Proteobacteria）和拟杆菌门（Bacteroidetes）相对丰度较高，分别为55.11%、21.32%。系统中具有反硝化作用的厚壁菌门（Firmicutes）相对丰度占比为2.81%，这可能是SBBR取得优秀脱氮效果的关键。在属水平下，系统中具有反硝化功能的菌种主要为Thauera和Limnobacter，在系统中占比分别为15.22%和2.84%，它们的存在可能是系统SND效果好的主要原因之一。

Advanced nitrogen removal efficiency of MSW leachate treated by SND with ASBR combined with SBBR process

In order to improve TN removal rate of leachate, the anaerobic sequencing batch reactor (ASBR) combined with the improved sequencing batch biofilm reactor (SBBR) process was used to treat the actual municipal solid waste (MSW) leachate with chemical oxygen demand (COD) of (5 700±500) mg/L and TN concentration of (210±50) mg/L. The results showed that the effluent of ASBR entered SBBR reactor for deep denitrification, and the main function was to adjust C/N of subsequent SBBR influent, and the removal rate of COD in leachate was 90%. C/N was the key to determining the nitrogen removal efficiency of SBBR. After adjusting the influent C/N to 4.8, under the action of biofilm, the deep denitrification of MSW leachate could be achieved only by anaerobic stirring and simultaneous nitrification and denitrification (SND) in the aerobic stage. The effluent total nitrogen concentration was lower than 10 mg/L, and the cycle running time was shortened from 24 hours on the 54th day to 5.6 hours. The best treatment effect could be achieved after 103 days of domestication and start-up of the whole system. The concentrations of COD, NH4 +-N and TN in the effluent were (380±10), (1.0±0.5) and (5±5) mg/L, respectively, and the removal rates were more than 93%, 99% and 95%, respectively. Through high-throughput sequencing analysis, the relative abundance of Proteobacteria and Bacteroides in the system was high, with 55.11% and 21.32%, respectively. In the system, the abundance of Firmicutes with denitrification accounted for 2.81%, which may be the key to achieving an excellent denitrification effect in SBBR. At the genus level, the bacteria with denitrification function in the system were mainly Thauera and Limnobacter, accounting for 15.22% and 2.84%, respectively. Their existence may be one of the main reasons for the good effect of the system SND. The system achieved deep denitrification of leachate without adding any carbon source and had high nitrogen removal efficiency, which provided an effective way for MSW leachate to meet the discharge standard of total nitrogen.