Interaction of graphene oxide nano-sheets and landfill leachate bacterial culture.

The interaction of graphene oxide (GO) and municipal landfill leachate bacterial culture was investigated. In aerobic conditions, stepwise addition of GO concentration to 60 mg/L increased the oxygen uptake rate coefficient. However, increasing the GO concentration to 100 mg/L slightly decreased the oxygen uptake rate coefficient. When anoxic conditions developed, GO suspensions decreased the total bacterial activity and the substrate consumption. Raman spectroscopy confirmed the chemical reduction of GO during exposure to bacteria; nonetheless, the extent of reduction in anoxic conditions was more than that in aerobic conditions. The chemical composition of landfill leachate showed to be able to also slightly reduce the GO after 10 days exposure, but the role of bacterial activity in the reduction process seemed to be dominant. As far as it could be seen under a light microscope, while the gram-positive bacteria were more vulnerable in anoxic assays, GO suspension did not affect the morphology and size of active cultures in the aerobic atmosphere.