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

ABSTRACT

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.

KEYWORDS:

• Landfill leachate
• graphene oxide
• biological interaction
• leachate bacteria
• biological oxygen demand

Acknowledgements

The authors would like to express their gratitude to the lab members at the University of Tehran and graduate faculty of environment who made this research possible. Helpful comments of the anonymous reviewers are also acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Nafise Jamialahmadi http://orcid.org/0000-0002-2419-3527

Additional information

Funding

The authors also express their gratitude to the Iran Nanotechnology Initiative Council and the Research Council of University of Tehran for partial funding of this work.