Nitrogen Removal and N.sub.2O Emission During Low Carbon Wastewater Treatment Using the Multiple A/O Process

• Published in: Water, air, and soil pollution air, and soil pollution, 2017-09, Vol.228 (9)
• Main Authors: Xing, Lizhen, Ou, Liying, Zhang, Yanhao, Zheng, Derui, Wu, Guangxue
• Format: Article
• Language: English
• Subjects: Denitrification; Emissions (Pollution); Nitrification; Nitrogen oxides; Phosphates; Sewage treatment; Waste treatment equipment
• ISSN: 0049-6979
• DOI: 10.1007/s11270-017-3446-x

With the organic carbon of acetate (SBR-A) and propionate (SBR-P), the effect of organic carbon sources on nitrogen removal and nitrous oxide (N.sub.2O) emission in the multiple anoxic and aerobic process was investigated. The nitrogen removal percentages in SBR-A and SBR-P reactor were both 72%, and the phosphate removal percentages were 97 and 85.4%, respectively. During nitrification, both the NH.sub.4.sup.+-N oxidation rate in the SBR-A and SBR-P had a small change without the influence of the addition of nitrite nitrogen (NO.sub.2.sup.--N). With the addition of 10 mg/L NO.sub.2.sup.--N, the nitrate nitrogen (NO.sub.3.sup.--N) production rate, N.sub.2O accumulation rate and emission factor had increased. At the same time, the N.sub.2O emission factor of SBR-A and SBR-P reactors increased from 2.13 and 0.87% to 4.66 and 2.08%, respectively. During exogenous denitrification, when nitrite was used as electron acceptor, the N.sub.2O emission factors were 34.1 and 8.6 times more than those of NO.sub.3.sup.--N as electron acceptor in SBR-A and SBR-P. During endogenous denitrification with NO.sub.2.sup.--N as electron acceptor, the accumulation rate and emission factor of N.sub.2O were higher than those of NO.sub.3.sup.--N as electron acceptor. High-throughput sequencing test showed that the dominant bacteria were Proteobacteria and Bacteroidetes in both reactors at the phylum level, while the main denitrification functional bacteria were Thauera sp., Zoogloea sp. and Dechloromonas sp. at the genus level.