Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
Sci Total Environ. 2021 Nov 20;796:148957. doi: 10.1016/j.scitotenv.2021.148957. Epub 2021 Jul 10.
Quaternary ammonium compounds have gained widespread attention due to their extensive enrichment in waste activated sludge (WAS) and potentially adverse effect to anaerobes. This study selected benzalkonium chlorides (BACs) as model to reveal the responses of anaerobic digestion of WAS to long-term stress of BACs. Results showed that the solubilization enhancement of WAS contributed by BACs was the acceleration of cell lysis, rather than the disruption of extracellular polymeric substances, and the accumulation improvement of short chain fatty acids (SCFAs) attributed to hydrolysis improvement and methanogenesis inhibition at either medium -or high level of BACs. In addition, a low level had no significant effect on the production of methane compared to control, with averages of 0.059 and 0.055 m/(m·d), respectively, whereas a medium level reduced methane production to 20% of control, and a high level almost completely inhibited methanogenesis. Correspondingly, BACs could shift microbial communities related to SCFAs and methane productions. For the bacterial community, a high level of BACs led to abundance reductions of Firmicutes, Bacteroidetes, Acidobacteria and Chloroflexi, but Synergistetes was increased to 10.5%, which was almost not detected either in control or at a low level of BACs. And for dominant archaeal community, they tended to be shifted from acetotrophic to hydrogenotrophic methanogens with BACs increasing from low to high level. These findings provided some new insights for the role of BACs in anaerobic digestion, as well as resource recovery from WAS.
季铵盐化合物由于其在废活性污泥（WAS）中的广泛富集以及对厌氧菌可能产生的不利影响而受到广泛关注。本研究选择苯扎氯铵（BACs）作为模型，以揭示 WAS 厌氧消化对 BACs 长期胁迫的响应。结果表明，BACs 对 WAS 的增溶作用是通过加速细胞裂解而不是破坏胞外聚合物物质来实现的，并且在 BACs 的中或高水平下，短链脂肪酸（SCFAs）的积累改善归因于水解的改善和产甲烷作用的抑制。此外，与对照组相比，低水平对甲烷的产生没有显著影响，平均值分别为 0.059 和 0.055 m/（m·d），而中水平将甲烷的产生降低到对照组的 20%，高水平几乎完全抑制了产甲烷作用。相应地，BACs 可以改变与 SCFAs 和甲烷产生相关的微生物群落。对于细菌群落，高水平的 BACs 导致厚壁菌门、拟杆菌门、酸杆菌门和绿弯菌门的丰度减少，但互营杆菌门增加到 10.5%，这在对照组或 BACs 的低水平下几乎没有检测到。对于主要的古菌群落，随着 BACs 从低水平增加到高水平，它们倾向于从乙酸营养型甲烷菌向氢营养型甲烷菌转移。这些发现为 BACs 在厌氧消化中的作用以及从 WAS 中回收资源提供了一些新的见解。
