低C/N进水城镇污水厂低溶解氧运行效能及微生物变化  

The efficiency and microbial community change of urban sewage plant with low C/N influent based on low DO strategy

作　　者：吴芳磊 贺航运 陈博涵 刘礼祥 李永 杜培坦 陈肖 WU Fanglei;HE Hangyun;CHEN Bohan;LIU Lixiang;LI Yong;DU Peitan;CHEN Xiao(Shenzhen Huanshui Investment Group Co.Ltd.,Shenzhen 518000,China;School of civil and environmental engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518000,China;Tengzhou Shenshui Shenteng Wastewater Treatment Co.Ltd.,Tengzhou 277500,China)

机构地区：[1]深圳市环水投资集团有限公司,深圳518000 [2]哈尔滨工业大学(深圳)土木与环境工程学院,深圳518000 [3]滕州市深水深滕污水处理有限公司,滕州277500

出　　处：《环境工程学报》2022年第8期2711-2719,共9页Chinese Journal of Environmental Engineering

摘　　要：低C/N进水污水厂通常需要外加碳源以保障脱氮除磷效能,运行费用高。本研究以摆脱低C/N污水处理对外碳源依赖及降低运营成本为目的,依托山东省某城镇污水厂(A^(2)O工艺)开展基于低DO调控策略的污水厂综合效能研究。结果表明,在长期低DO运行策略下,污水厂逐渐停止外加碳源,在硝化液回流比由370%逐渐降至90%的过程中,TN平均去除率由76.3%提升至82.9%,且除磷效率有所提升。对好氧区氮平衡进行分析发现,在低DO运行条件下,好氧区NH_(4)^(+)-N的转化逐渐以短程硝化和同步反硝化作用为主。微生物宏基因组学结果表明,在低DO条件下,NOB丰度由0.15%下降至0.06%,而具备反硝化功能的PAOs与GAOs的总体丰度由2.06%升高至3.57%。长期低DO、无外加碳源运行条件下,脱氮效能的显著提升主要由于好氧区短程硝化和同步反硝化作用的比例升高所致。低DO对AOB抑制作用小,对NOB抑制作用显著,导致NO_(2)^(−)-N的积累,保障了脱氮效能;PAOs与GAOs利用厌氧期储存的内碳源在好氧区反硝化脱氮,提升了脱氮效能;而内碳源利用率的提升又促进了PAOs的生长,提升了除磷效能。此外,污水厂低DO运行策略下,节省了运营成本,吨水处理费用降低了0.3元。Low C/N influent wastewater plants usually need additional carbon source to ensure nitrogen and phosphorus removal efficiency,leading to the high operation cost.In order to get rid of external carbon sources for low C/N wastewater treatment and reduce operation cost,a comprehensive efficiency study was carried out in an urban wastewater treatment plant with A^(2)O process in Shandong Province based on low DO regulation strategy.The results showed that under the long-term low DO operation strategy,when the wastewater plant gradually stopped additional carbon sources and decreased the reflux ratio of nitrification liquid from 370%to 90%,TN average removal rate increased from 76.3%to 82.9%,and phosphorus removal effect also increased.The analysis of nitrogen balance in aerobic zone showed that the transformation of NH_(4)^(+)-N in aerobic zone was gradually dominated by partial nitrification and simultaneous denitrification under low DO condition.Microbial metagomenomics results showed that under low DO condition,the abundance of NOB decreased from 0.15%to 0.06%,while the total abundance of PAOs and GAOs with denitrifying function increased from 2.06%to 3.57%.The significant improvement of nitrogen removal efficiency under long-term low DO and no external carbon source was mainly due to the increased proportion of partial nitrification and simultaneous denitrification in aerobic zone.Low DO had slight inhibitory effect on AOB,while inhibited NOB significantly,resulting in NO_(2)^(−)-N accumulation and ensuring TN removal efficiency.PAOs and GAOs used the internal carbon source stored in the anaerobic stage for denitrification in the aerobic zone,which improved the denitrification efficiency.The improvement of internal carbon source utilization rate promoted the growth of PAOs and raised phosphorus removal efficiency.In addition,under the low DO operation strategy of the sewage plant,the operating cost was saved and the wastewater treatment cost was reduced by 0.3 yuan per ton wastewater.

关 键 词：低溶解氧 低碳氮比 碳源 短程硝化 同步反硝化 

分 类 号：X703.1[环境科学与工程—环境工程]