Effect of DO concentration on the combination of EBPR and SND for low C/N sewage treatment
ZHAO Ji, WANG Xiao-xia, LI Xi-yao, PENG Yong-zhen, JIA Shu-yuan
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China
Abstract：This study focused on investigating the nitrogen (N) and phosphorus removal characteristics of a combined enhanced phosphorus removal (EBPR) with simultaneous nitrification and denitrification (SND) process. An anaerobic/aerobic operated sequencing batch reactor (SBR), fed with actual domestic sewage at a low carbon/nitrogen ratio (C/N, around 3.5), was studied firstly for the start-up of EBPR and the enrichment of phosphorus accumulating organisms (PAOs) by adjusting the influent C/N, and lately for the nutrient removal performance, SND efficiency, and carbon sources conversion by adjusting the dissolved oxygen (DO) concentrations at the aerobic stage. Results showed that at DO concentration of around 2.0mg/L and influent C/N increased from 3.2 to 7.5and then recovered to 3.8, effluent PO43--P concentration gradually decreased from 3.9mg/L to below 0.5mg/L accompanied by the increase of anaerobic phosphorus release amount (PRA) from 3.3mg/L to approximately 30mg/L. Hereafter, when DO concentration gradually decreased to about 1.0mg/L, SND became obvious, and its coupling with EBPR increased the total nitrogen (TN) and PO43--P removal efficiencies to 85% and 94%, respectively. But when the DO concentration was continued decreased to about 0.5mg/L, nitrification became incomplete and nitrite accumulation became obvious, indicating the existence of simultaneous partial nitrification and denitrification. The results indicated that the combined system has the highest nitrogen and phosphorus removal performance at DO concentration of about 1.0mg/L. In addition, when DO concentration decreased from 2.0mg/L to 0.5mg/L, the contribution of PAOs to the storage of anaerobic intracellular carbon sources (PPAO,An) gradually reduced from 30.3% to 20.2%, resulted in a decrease of PRA for about 7mg/L. DO concentration of 1.0~1.5mg/L was the most conducive to the synthesis of carbon source PHA in the anaerobic stage of the combined system.
赵骥, 王晓霞, 李夕耀, 彭永臻, 贾淑媛. DO浓度对EBPR耦合SND处理低C/N污水的影响[J]. 中国环境科学, 2018, 38(1): 120-128.
ZHAO Ji, WANG Xiao-xia, LI Xi-yao, PENG Yong-zhen, JIA Shu-yuan. Effect of DO concentration on the combination of EBPR and SND for low C/N sewage treatment. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(1): 120-128.
Grocetti G R, Hugenholtz P, Bond P L, et al. Identification of polyphosphate accumulating organisms and design of 16SrRNAdirected probes for their detection and quantitation[J]. Applied and Enviromental Microbiology, 2000,66(3):1175-1182.
[3]
Munch E, Lant P, Keller J. Simultaneous Nitrification and Denitrification in Bench-scale Sequencing Batch Reactors[J]. Water Research, 1996,30(2):277-284.
[4]
Masuda S, Watanabe Y, Ishiguro M. Biofilm Properties and Simultaneous Nitrification and Denitrification in Aerobic Rotating Biological Contactors[J]. Water Science and Technology, 1991,23(7):1355-1363.
[5]
Rittmann B, Langeland W. Simultaneous Denitrification with Nitrification in Single-channel Oxidation Ditches[J]. Journal Water Pollution Control Federation, 1985,57(4):300-308.
Goronszy M, Demoulin G, Newland M. Aerated Denitrification in Full-scale Activated Sludge Facilities[J]. Water Science and Technology, 1997,35(10):103-110.
Wang X X, Wang S Y, Xue T L, et al. Treating low carbon/nitrogen (C/N) wastewater in simultaneous nitrificationendogenous denitrification and phosphorous removal (SNDPR) systems by strengthening anaerobic intracellular carbon storage[J]. Water Research, 2015,77:191-200.
Wang X X, Wang S Y, Zhao J, et al. A novel stoichiometries methodology to quantify functional microorganisms in simultaneous nitrification-endogenous denitrification and phosphorous removal (SNEDPR)[J]. Water Research, 2015,95:319-329.
Amann R I, Krumholz L, Stahl D A. Fluorescent-oligonucleotide probing of whole cells for determinative, phylogenetic, and environmental studies in microbiology[J]. Journal of Bacteriology, 1990,172(2):762-770.
Grocetti G R, Hugenholtz P, Bond P L, et al. Identification of polyphosphate accumulating organisms and design of 16SrRNAdirected probes for their detection and quantitation[J]. Applied and Enviromental Microbiology, 2000,66(3):1175-1182.
Zeng R J, Lemaire R, Yuan Z G, et al. Simultaneous nitrification, denitrification, and phosphorus removal in a lab-scale sequencing batch reactor[J]. Biotechnology and Bioengineering, 2003,84(2):170-178.
Coma M, Verawaty M, Pijuan M, et al. Enhancing aerobic granulation for biological nutrient removal from domestic wastewater[J]. Bioresource Technology, 2012,103(1):101-108.
