Effect of aeration on low-substrate CANON process  

作　　者：Qiong-qiong Xia Wei Shang Xing-can Zheng Wen-an Zhang Ya-xiong Wang Yong-li Sun Peng-feng Li 

机构地区：[1]North China Municipal Engineering Design&Research Institute Co.,Ltd.,Tianjin 300074,China

出　　处：《Water Science and Engineering》2024年第3期292-299,共8页水科学与水工程(英文版)

基　　金：supported by the China National Science and Technology Major Project for Water Pollution Control and Treatment(Grant No.2017ZX07106005).

摘　　要：The completely autotrophic nitrogen removal over nitrite(CANON)is a new type of nitrogen removal process developed in recent years.The control of dissolved oxygen(DO)in this process is relatively stringent,especially in low-substrate wastewater treatment.However,the results of studies on the operation of the process in different aeration modes are still controversial,and investigations on biofilm type CANON reactors are limited.In this study,a pilot-scale CANON bioreactor filled with suspended carriers was investigated on the treatment of wastewater at low ammonium concentrations,and the effect of the aeration mode on autotrophic nitrogen removal was evaluated.Seven conditions with various aeration on/off times and DO levels were tested.The results showed that an intermittent aeration with a 20-min/20-min aeration on/off time and DO concentrations of 1.0-1.3 mg/L at the end of the aeration period was appropriate,potentially inhibiting nitrite oxidizing bacteria(NOB)and keeping the total nitrogen(TN)removal rate at a relatively high level of 76.7%±2.5%.In the optimal aeration mode,the reactor achieved effluent TN and NH_(4)^(+)-N concentrations of(11.1±3.3)mg/L and(3.6±2.3)mg/L,respectively,with a hydraulic retention time of 12 h and an influent NH_(4)^(+)-N concentration of(48.6±9.4)mg/L at 30.1℃±2.2℃.The results of metagenomic sequencing for microorganisms on carriers indicated that the main nitrogen removal bacteria in the reactor were Proteobacteria,Planctomycetes,and Nitrospirae.The NOB genus Nitrospira was completely inhibited by intermittent aeration.Candidatus Kuenenia had strong adaptability to low-concentration wastewater.

关 键 词：CANON Suspended carriers Intermittent aeration Characteristics of microbial communities NOB inhibition 

分 类 号：X70[环境科学与工程—环境工程]