梯度曝气A^(2)O^(2)-MBR工艺强化同步硝化反硝化效能  

Enhanced SND performance of step-wise aeration A^(2)O^(2)-MBR process

作　　者：刘钢 王丽 温榛煌 谌建宇 黎京士 何伟 梅嘉鑫 张宇 LIU Gang;WANG Li;WEN Zhenhuang;CHEN Jianyu;LI Jingshi;HE Wei;MEI Jiaxin;ZHANG Yu(South China Institute of Environmental Science,Ministry of Ecology and Environment,Guangzhou 510655,China;China Construction Fourth Engineering Division Co.Ltd.,Guangzhou 510000,China;Guangdong Polytechnic of Environmental Protection Engineering,Foshan 528216,China)

机构地区：[1]生态环境部华南环境科学研究所,广州510655 [2]中国建筑第四工程局有限公司,广州510000 [3]广东环境保护工程职业学院,佛山528216

出　　处：《环境工程学报》2024年第4期1130-1143,共14页Chinese Journal of Environmental Engineering

基　　金：中央级公益性科研院所基本科研业务专项(PM-zx703-202104-130);中建四局科技研发课题(CSCEC4B-2021-KTA-6)。

摘　　要：针对城镇污水厂对低C/N比污水脱氮效果差、能耗高的问题,研发了梯度曝气A^(2)O^(2)-MBR工艺,设置单独的低氧池(O_(1)池)和好氧池(O_(2)池),O_(1)和O_(2)池DO质量浓度逐步降至0.6 mg·L^(-1)和1.7 mg·L^(-1)。进水碳氮比(C/N)从6.0逐步降至5.0和4.0,总氮(TN)去除率保持在85%左右。O_(1)和O_(2)池同步硝化反硝化效率保持在90%左右,O池(O_(1)池+O_(2)池)和膜池对TN去除的贡献在82.5%以上,对COD去除的贡献在64.9%~83.2%。高通量测序结果表明,在低DO低C/N比条件下,系统中亚硝酸盐氧化菌(nitrite-oxidizing bacteria,NOB)丰度下降,反硝化聚糖菌(denitrifying glycogen accumulating organisms,DGAOs)丰度增加;反硝化菌类群丰富,其中Pseudomonas的丰度最高,Thauera和Zoogloea在低C/N比条件下丰度增加。大部分TN通过常规异养反硝化菌(denitrifyingbacteria,DNB)去除,DGAOs的贡献较小。与启动阶段相比,O_(1)池和O_(2)池总曝气量下降了44.2%。结果表明,通过采用梯度曝气方式,并逐步降低DO浓度,可促进功能菌的富集,强化SND作用,改善TN去除效果,并降低能耗。Aiming at poor denitrification effect and high energy consumption when treating the wastewater with the low C/N ratio in wastewater treatment plant(WWTPs),a step-wise aeration A^(2)O^(2)-MBR process was developed.The separated low-oxic zone(O_(1))and oxic zone(O_(2))were design with the DO concentrations decreased gradually to 0.6 mg·L^(-1)and 1.7 mg·L^(-1),respectively.When the influent C/N ratio decreased from 6.0 to 5.0 and 4.0,the total nitrogen(TN)removal efficiency maintained at around 85%.The simultaneous nitrification and denitrification(SND)efficiency of the O_(1)and O_(2)zones kept at around 90%.Both O zones(O_(1)+O_(2))and membrane zones contributed to above 82.5%of TN removal,and 64.9%~83.2%of COD removal.High-throughput gene sequencing showed that,under low DO and low C/N ratio conditions,the abundance of nitrite-oxidizing bacteria(NOB)decreased,while the abundance of denitrifying glycogen accumulating organisms(DGAOs)increased.Rich denitrifiers occurrred,of which the abundance of Pseudomonas was highest.Besides,the abundance of Thauera and Zoogloea increased under low C/N ratio condition.Most of TN was removed by ordinary denitrifying bacteria(DNB),rather than DGAOs.Compared with the startup stage,the total aeration rate of the O_(1)and O_(2)zones decreased by 44.2%.The results showed that the step-wise aeration mode could gradually lower the DO concentrations,enrich the functional bacteria,then enhance the SND effect,increase TN removal,save the energy consumption.

关 键 词：城镇污水 生物脱氮 同步硝化反硝化 溶解氧控制 高通量测序 

分 类 号：X703.1[环境科学与工程—环境工程]