School of Ecology and Environment, Zhengzhou University, Kexue Road 100, Zhengzhou, 450001, China.
School of Water Conservancy and Transportation, Zhengzhou University, Kexue Road 100, Zhengzhou, 450001, China.
J Environ Manage. 2024 Nov;370:122771. doi: 10.1016/j.jenvman.2024.122771. Epub 2024 Oct 2.
Red mud (RM) as hazardous waste produced from aluminum refining industry has threatened the environment and human health. In this study, RM was added into the fermenter to promote short chain fatty acids (SCFAs) production from waste activated sludge (WAS) anaerobic fermentation. Results showed that the addition of RM could effectively improve the SCFAs production, especially, acetic acid. In particular, the production of total SCFAs and acetic acid in 20 g/L RM added fermenter were 1108.1 mg COD/L and 415.5 mg COD/L, which were 116.0% and 1308.0% higher than that in control fermenter. Batch experiment revealed that RM could enhance the hydrolysis and acidification process. Further study indicated that the activity of enzyme related to hydrolysis-acidification, abundance of fermentative bacteria for SCFAs production and functional metabolism genome were all improved with the addition of RM. The potential mechanism maybe that the RM promoted the hydrolysis-acidification process with the contained varies Fe(Ⅲ) oxides as electron acceptor, and the produced Fe could serve as necessary trace elements to synthesize enzyme and then stimulate the expression of enzyme genes.
赤泥（RM）作为铝精炼工业产生的危险废物，已经对环境和人类健康构成了威胁。在这项研究中，将 RM 添加到发酵罐中，以促进废活性污泥（WAS）厌氧发酵中短链脂肪酸（SCFAs）的生成。结果表明，添加 RM 可以有效地提高 SCFAs 的生成，特别是乙酸。特别是，在添加 20g/L RM 的发酵罐中，总 SCFAs 和乙酸的生成量分别为 1108.1mg COD/L 和 415.5mg COD/L，分别比对照发酵罐提高了 116.0%和 1308.0%。批处理实验表明，RM 可以增强水解酸化过程。进一步的研究表明，与水解酸化相关的酶活性、产生 SCFAs 的发酵细菌的丰度以及功能代谢基因组都随着 RM 的添加而得到了改善。其潜在的机制可能是 RM 促进了水解酸化过程，其中包含的各种 Fe(Ⅲ)氧化物作为电子受体，而产生的 Fe 可以作为合成酶的必需微量元素，从而刺激酶基因的表达。
