Abstract Using the acclimated activated sludge from the pulping middle-stage effluent, the effect of pH shock on the micro-oxygen activated sludge system with a nano-magnetic powder/graphene oxide composite was studied. The results showed that the removal rates of chemical oxygen demand (CODCr) and ultraviolet adsorption at 254 nm (UV254) decreased. Also, the sludge settling performance was poor due to the impact of pH, but the impact resistance of nano-magnetic powder/graphene oxide group (MGO group) was higher and the recovery was faster. Results of high throughput sequencing indicated that the diversity of microbial community was reduced by the impact of pH, but it was significantly higher in MGO group than in the blank group. The dominant bacteria after pH shock or recovery in both of the system had a large difference. The percentage of the dominant bacteria in the MGO group was higher than that in the blank group. The MGO group had higher electron transfer system (ETS) activity which made the system having a strong pH impact resistance.

中文翻译：

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pH冲击对氧化石墨烯/纳米磁粉复合微好氧活性污泥体系的影响

摘要 利用制浆中段出水驯化的活性污泥，研究了pH冲击对纳米磁粉/氧化石墨烯复合微氧活性污泥系统的影响。结果表明，化学需氧量（CODCr）的去除率和254 nm处的紫外线吸收率（UV254）降低。此外，由于pH的影响，污泥沉降性能较差，但纳米磁粉/氧化石墨烯基团（MGO基团）的抗冲击性更高，恢复更快。高通量测序结果表明，微生物群落的多样性受pH的影响降低，但MGO组显着高于空白组。pH冲击或恢复后两种系统的优势菌存在较大差异。MGO组优势菌百分比高于空白组。MGO基团具有较高的电子转移体系（ETS）活性，使体系具有较强的抗pH冲击能力。