The accelerated development and application of graphene-family nanomaterials (GFNs) have increased their release to various environments and converged in wastewater treatment plants (WWTPs). However, little is known about the interactions between GFNs and microbes in WWTPs. In this study, the interaction of graphene oxide (GO) or graphene (G) at different concentrations with microbial communities in sequential batch reactors was investigated. Transmission electron microscopy and Raman spectroscopy analyses showed that the structures of GFNs were obviously changed, which suggested GFNs could be degraded by some microbes. Significantly higher DNA concentration and lower cell number in high-concentration GO group were detected by DNA leakage test and qPCR analysis, which confirmed the microbial toxicity of GO. The chemical oxygen demand and ammonia nitrogen removals were significantly affected by G and GO with high concentrations. Further, high-throughput sequencing confirmed the composition and dynamic changes of microbial communities under GFNs exposure. Saccharibacteria genera incertae sedis (12.55–28.05%) and Nakamurella (20.45–29.30%) were the predominant genera at two stages, respectively. FAPROTAX suggested 12 functional groups with obvious changes related to the biogeochemical cycle of C, N and S. Molecular ecological network analysis showed that the networks were more complex in the presence of GFNs, and the increased negative interactions reflected more competition relationships in microbial communities. This study is the first to report the effect of GFNs on network of microbial communities, which provides in-depth insights into the complex and highlights concerns regarding the risk of GFNs to WWTPs.

石墨烯族纳米材料（GFN）的加速开发和应用已经增加了它们向各种环境的释放，并集中在废水处理厂（WWTP）中。然而，关于污水处理厂中GFN与微生物之间相互作用的了解甚少。在这项研究中，研究了顺序分批反应器中不同浓度的氧化石墨烯（GO）或石墨烯（G）与微生物群落的相互作用。透射电子显微镜和拉曼光谱分析表明，GFN的结构发生了明显变化，表明GFN可能被某些微生物降解。通过DNA渗漏试验和qPCR分析，高浓度GO组的DNA浓度显着升高，而细胞数则降低，证实了GO的微生物毒性。高浓度的G和GO对化学需氧量和氨氮去除的影响很大。此外，高通量测序证实了GFN暴露下微生物群落的组成和动态变化。葡萄球菌属不活菌（12.55–28.05％）和纳卡氏菌（20.45–29.30％）分别是两个阶段的主要属。FAPROTAX提出了12个官能团，这些官能团与C，N和S的生物地球化学循环有明显的变化。分子生态网络分析表明，存在GFN时，网络更为复杂，负向相互作用的增加反映了微生物群落之间更多的竞争关系。这项研究是第一个报告GFN对微生物群落网络的影响的研究，该研究提供了对该复合物的深入了解，并突出了有关GFN对污水处理厂的风险的担忧。