Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041, PR China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Chengdu, 610041, PR China.
Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041, PR China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Chengdu, 610041, PR China.
J Environ Manage. 2024 Oct;369:122357. doi: 10.1016/j.jenvman.2024.122357. Epub 2024 Sep 3.
A large amount of greenhouse gas nitrous oxide (NO) will be produced during the biological nitrogen removal process for organic wastewater of low C/N ratio. One of the effective methods to solve this problem is to incorporate inexpensive carbon source. In this study, raw wastewater (RW) from pig farm, that was not anaerobically digested, was utilized as exogenous carbon in both A/O and SBR aerobic reactor to treat liquid digestate with high ammonia nitrogen and low C/N ratio. The results showed that NO emission in SBR was higher than that of A/O process under the same nitrogen load. The NO conversion in the biological nitrogen removal process was investigated by the strategy of integrating stable isotope method and metagenomics. The δO-NO, δN-NO, and SP values of the SBR were closer to the denitrification values of Ammonia-Oxidizing Bacteria (AOB) than those of A/O. The abundance of AOB in the SBR reactor was higher than that in the A/O reactor, while the abundance of denitrifying bacteria was lower. The amoA/B/C gene abundance in the SBR was greater than that in the A/O, and the NOS gene abundance was the opposite. The results indicated that both AOB denitrification and bacterial denitrification led to the increase of NO emissions of the SBR.
大量的温室气体氧化亚氮（NO）将在低 C/N 比的有机废水的生物脱氮过程中产生。解决这个问题的有效方法之一是加入廉价的碳源。在这项研究中，未进行厌氧消化的猪场原水（RW）被用作 A/O 和 SBR 好氧反应器中的外源碳，以处理高氨氮和低 C/N 比的液体消化液。结果表明，在相同的氮负荷下，SBR 中的 NO 排放高于 A/O 工艺。通过整合稳定同位素法和宏基因组学的策略，研究了生物脱氮过程中的 NO 转化。SBR 的δO-NO、δN-NO 和 SP 值比 A/O 更接近氨氧化菌（AOB）的反硝化值。SBR 反应器中 AOB 的丰度高于 A/O 反应器，而反硝化菌的丰度较低。SBR 中的 amoA/B/C 基因丰度大于 A/O，NOS 基因丰度则相反。结果表明，AOB 反硝化和细菌反硝化都会导致 SBR 中 NO 排放的增加。
