Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, China.
Environmental Science and Engineering, Biological and Environmental Sciences & Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
Appl Environ Microbiol. 2024 Apr 17;90(4):e0225323. doi: 10.1128/aem.02253-23. Epub 2024 Mar 5.
We evaluated a unique model in which four full-scale wastewater treatment plants (WWTPs) with the same treatment schematic and fed with similar influent wastewater were tracked over an 8-month period to determine whether the community assembly would differ in the activated sludge (AS) and sand filtration (SF) stages. For each WWTP, AS and SF achieved an average of 1-log (90%) and <0.02-log (5%) reduction of total cells, respectively. Despite the removal of cells, both AS and SF had a higher alpha and beta diversity compared to the influent microbial community. Using the Sloan neutral model, it was observed that AS and SF were individually dominated by different assembly processes. Specifically, microorganisms from influent to AS were predominantly determined by the selective niche process for all WWTPs, while the microbial community in the SF was relatively favored by a stochastic, random migration process, except two WWTPs. AS also contributed more to the final effluent microbial community compared with the SF. Given that each WWTP operates the AS independently and that there is a niche selection process driven mainly by the chemical oxygen demand concentration, operational taxonomic units unique to each of the WWTPs were also identified. The findings from this study indicate that each WWTP has its distinct microbial signature and could be used for source-tracking purposes.IMPORTANCEThis study provided a novel concept that microorganisms follow a niche assembly in the activated sludge (AS) tank and that the AS contributed more than the sand filtration process toward the final microbial signature that is unique to each treatment plant. This observation highlights the importance of understanding the microbial community selected by the AS stage, which could contribute toward source-tracking the effluent from different wastewater treatment plants.
我们评估了一个独特的模型，其中四个具有相同处理方案且以相似进水废水为进水的全规模污水处理厂（WWTP）在 8 个月的时间内进行了跟踪，以确定活性污泥（AS）和砂滤（SF）阶段的群落组装是否会有所不同。对于每个 WWTP，AS 和 SF 分别实现了平均 1 对数（90%）和 <0.02 对数（5%）的总细胞去除。尽管去除了细胞，但 AS 和 SF 的α多样性和β多样性均高于进水微生物群落。使用 Sloan 中性模型观察到，AS 和 SF 分别由不同的组装过程主导。具体而言，对于所有 WWTP，从进水到 AS 的微生物主要由选择性生态位过程决定，而 SF 中的微生物群落则相对有利于随机、随机迁移过程，除了两个 WWTP。与 SF 相比，AS 对最终出水微生物群落的贡献也更大。鉴于每个 WWTP 独立运行 AS，并且存在主要由化学需氧量浓度驱动的生态位选择过程，因此还确定了每个 WWTP 特有的操作分类单元。本研究的结果表明，每个 WWTP 都有其独特的微生物特征，可以用于源追踪目的。
重要性
本研究提出了一个新的概念，即微生物在活性污泥（AS）罐中遵循生态位组装，并且 AS 比砂滤过程对每个处理厂特有的最终微生物特征的贡献更大。这一观察结果强调了理解 AS 阶段选择的微生物群落的重要性，这有助于追踪不同污水处理厂的出水来源。
