State Key Laboratory of Petroleum Pollution Control, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum-Beijing, Beijing, 102249, China.
Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Key Laboratory of Petrochemical Pollution Control of Guangdong Higher Education Institutes, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China.
J Environ Manage. 2022 Dec 15;324:116317. doi: 10.1016/j.jenvman.2022.116317. Epub 2022 Sep 28.
Volatile fatty acids (VFA), produced from waste activated sludge (WAS), provide unique opportunities for resource recovery in wastewater treatment plants. This study investigates the potential of refinery spent caustic (RSC) on VFA production during refinery WAS (RWAS) alkaline fermentation. The highest VFA yield was 196.3 mg/g-VS at a sludge retention time of 6 days. Amplicon sequencing revealed the enrichment of Soehngenia (20.21%), Bacilli (11.86%), and Brassicibacter (4.17%), which was associated with improved activities of protease (626%) and α-glucosidase (715%). Function prediction analysis confirmed that acetyl-CoA production and fatty acid biosynthesis were enhanced, while fatty acid degradation was inhibited. Accordingly, hydrolysis, acidogenesis, and acetogenesis were improved by 6.87%, 10.67%, and 28.50%, respectively; whereas methanogenesis was inhibited by 28.87%. The sulfate and free ammonia in RSC likely contributed to increased acetic acid production. This study showcases that RWAS alkaline fermentation mediated by RSC for VFA production is the practicable approach.
挥发性脂肪酸（VFA）由废活性污泥（WAS）产生，为污水处理厂的资源回收提供了独特的机会。本研究探讨了精炼废碱（RSC）在炼油厂废活性污泥（RWAS）碱性发酵过程中对 VFA 生产的潜力。在污泥停留时间为 6 天时，VFA 的最高产量为 196.3mg/g-VS。扩增子测序显示，Soehngenia（20.21%）、芽孢杆菌（11.86%）和 Brassicibacter（4.17%）得到了富集，这与蛋白酶（626%）和α-葡萄糖苷酶（715%）活性的提高有关。功能预测分析证实，乙酰辅酶 A 的产生和脂肪酸的生物合成得到了增强，而脂肪酸的降解受到了抑制。因此，水解、产酸和产乙酸分别提高了 6.87%、10.67%和 28.50%；而甲烷生成受到了 28.87%的抑制。RSC 中的硫酸盐和游离氨可能有助于增加乙酸的产生。本研究表明，RWAS 碱性发酵介导的 RSC 用于 VFA 生产是可行的方法。
