A moving bed biofilm reactor (MBBR) is an efficient water treatment process, widely used in recirculating aquaculture systems. The optimization of relevant parameters to shorten the start-up period and improve the performance of the MBBR is an ongoing research hotspot. In this study, a new aquaculture wastewater pretreatment process, the electrocoagulation–air flotation–microfiltration technology (EC–AF–MF), was constructed, and its effects on the MBBR start-up, performance, and microbial community structure were investigated. The electrocoagulation–air flotation (EC–AF) process significantly increased the particle size of total suspended solids (TSS), thereby enhancing the microscreen drum filter's removal efficiency (RE) for TSS. In addition, EC altered the microbial community and improved the MBBR's RE for TSS, chemical oxygen demand (COD), and total ammonia nitrogen (TAN). Interestingly, the Fe anode produced better results. The REs for TSS, COD, and TAN in the Fe group were 89.27 ± 0.30%, 69.99 ± 1.13%, and 100%, respectively. The Fe anode accelerated not only the biofilm formation and stability but also the start-up of the MBBR. These findings indicate that the EC(Fe anode)–AF–MF process could shorten the start-up period and enhance the performance of the MBBR, providing a reference for the standard treatment of aquaculture wastewater and promoting an ecologically sustainable aquaculture industry.

中文翻译：

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电凝-气浮-微滤预处理工艺对移动床生物膜反应器启动的影响：性能和微生物群落结构

移动床生物膜反应器（MBBR）是一种高效的水处理工艺，广泛应用于循环水产养殖系统。通过优化相关参数来缩短MBBR的启动周期、提高其性能是目前的研究热点。本研究构建了一种新的水产养殖废水预处理工艺——电絮凝-气浮-微滤技术（EC-AF-MF），并研究了其对MBBR启动、性能和微生物群落结构的影响。电凝-气浮（EC-AF）工艺显着增加了总悬浮固体（TSS）的粒径，从而提高了微筛转鼓过滤器对TSS的去除效率（RE）。此外，EC 改变了微生物群落并提高了 MBBR 对 TSS、化学需氧量 (COD) 和总氨氮 (TAN) 的 RE。有趣的是，铁阳极产生了更好的结果。 Fe 组中 TSS、COD 和 TAN 的 RE 分别为 89.27 ± 0.30%、69.99 ± 1.13% 和 100%。 Fe阳极不仅加速了生物膜的形成和稳定性，而且加速了MBBR的启动。这些研究结果表明，EC（Fe阳极）-AF-MF工艺可以缩短MBBR的启动周期，提高MBBR的性能，为水产养殖废水的规范处理提供参考，促进水产养殖业的生态可持续发展。