Worldwide graphene use is rapidly increasing in a variety of industrial applications to such an extent that efflux into the environment seems inevitable where the likely final reservoirs of graphene wastes is likely to be wastewater treatment plants are. Despite this an understanding of how graphene products impact the bioleaching of metals from sludge is still limited. In this study, the effect of reduced graphene oxide synthesized from eucalyptus leaf extracts (EL-rGO) on Zn²⁺ and Cu²⁺ bioleaching from sludge was investigated. The major new findings were that EL-rGO had a negative effect on Acidithiobacillus ferrooxidans (A. ferrooxidans) growth; since optical density decreased by 0.059 as EL-rGO dose increased from 1 to 50 mg/L, and the bioleaching of Cu²⁺ and Zn²⁺ decreased by 27.7 and 20.2%, respectively. While at a EL-rGO dose of 1 mg/L A. ferrooxidans grew better, scanning electron microscopy (SEM) confirmed that exposure to EL-rGO caused cell membrane disruption at 50 mg/L. Cytotoxicity tests showed that this was related to an increase in lactate dehydrogenase (LDH) release rate and a decrease in superoxide dismutase (SOD) activity. These new findings provide evidence that green synthesized rGO is toxic to microorganisms and that toxicity increased with rGO dose.

在各种工业应用中，世界范围内石墨烯的使用正在迅速增加，以至于不可避免的是向环境中的外排，而石墨烯废物的最终最终储存库很可能是废水处理厂。尽管如此，对石墨烯产品如何影响污泥中金属生物浸出的理解仍然有限。在这项研究中，研究了从桉树叶提取物（EL-rGO）合成的还原氧化石墨烯对污泥中Zn ²⁺和Cu ²⁺生物浸出的影响。新的主要发现是，EL-rGO对酸性氧化铁硫杆菌（A. ferrooxidans）的生长有负面影响。因为随着EL-rGO剂量从1增加到50 mg / L，光密度降低了0.059，并且Cu ²⁺的生物浸出Zn ²⁺和Zn ^2+分别降低了27.7％和20.2％。在EL-rGO剂量为1 mg / L的条件下，四氧化二铁的生长更好，但扫描电子显微镜（SEM）证实，暴露于EL-rGO会使50 mg / L的细胞膜破裂。细胞毒性测试表明，这与乳酸脱氢酶（LDH）释放速率的增加和超氧化物歧化酶（SOD）活性的降低有关。这些新发现提供了证据，证明绿色合成的rGO对微生物有毒性，并且毒性随rGO剂量增加而增加。