The present study investigates the chronic toxicity of graphene (G) and graphene oxide (GO) in activated sludge. Sequencing batch bioreactors were fed with influents containing 0, 1 and 5 mg L⁻¹ of GO or G (12 h cycles) for ten days. Reduction in performance of the bioreactors in relation to chemical oxygen demand, ammonia and phosphate removals was observed after three days in the bioreactors fed with 5 mg L⁻¹ of nanomaterials. After about eight days, these reactors reached a steady state nutrient removal, which corresponded to recovery of certain groups of ammonia oxidizing bacteria and phosphate accumulating bacteria despite the increasing accumulation of nanomaterials in the sludge. These results suggested that biological treatment can be affected transiently by initial exposure to the nanomaterials, but certain groups of microorganisms, less sensitive to these nanomaterials, can potentially strive in the presence of these nanomaterials.

Results

of 16S rRNA gene deep sequencing showed that G and GO affected differently the microbial communities in the activated sludge. Between the two nanomaterials investigated, GO presented the highest impact in nutrient removal, gene abundance and changes in microbial population structures.

中文翻译：

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石墨烯和氧化石墨烯在分批批量生物反应器中的慢性毒性：比较研究

本研究调查了活性污泥中石墨烯（G）和氧化石墨烯（GO）的慢性毒性。向测序分批生物反应器中喂入含有0、1和5 mg L ^-1的GO或G的进水（12小时循环），持续10天。在饲喂5 mg L ^-1的生物反应器中，三天后观察到与化学需氧量，氨和磷酸盐去除量有关的生物反应器性能下降。纳米材料。大约八天后，这些反应器达到了稳定的营养去除率，尽管污泥中纳米材料的积累量不断增加，这对应于某些组氨氧化细菌和磷酸盐积累细菌的回收。这些结果表明，生物处理可以通过最初暴露于纳米材料而短暂地受到影响，但是某些对这些纳米材料不太敏感的微生物组可以在存在这些纳米材料的情况下进行潜在的努力。

结果

16S rRNA基因的深度测序表明，G和GO对活性污泥中微生物群落的影响不同。在所研究的两种纳米材料之间，GO在营养去除，基因丰度和微生物种群结构变化方面表现出最大的影响。