The inhibitory impacts of nano-graphene oxide on methane production from waste activated sludge in anaerobic digestion

Bin Dong; Zhaohui Xia; Jing Sun; Xiaohu Dai; Xueming Chen; Bing-Jie Ni

doi:10.1016/j.scitotenv.2018.07.424

The inhibitory impacts of nano-graphene oxide on methane production from waste activated sludge in anaerobic digestion

Sci Total Environ. 2019 Jan 1:646:1376-1384. doi: 10.1016/j.scitotenv.2018.07.424. Epub 2018 Jul 31.

Authors

Bin Dong¹, Zhaohui Xia¹, Jing Sun², Xiaohu Dai¹, Xueming Chen³, Bing-Jie Ni⁴

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
² State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: jingsun@tongji.edu.cn.
³ Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
⁴ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: bjni@tongji.edu.cn.

PMID: 30235623
DOI: 10.1016/j.scitotenv.2018.07.424

Abstract

The wide application of graphene oxide nanoparticles inevitably leads to their discharge into wastewater treatment plants and combination with the activated sludge. However, to date, it is largely unknown if the nano-graphene oxide (NGO) has potential impacts on the anaerobic digestion of waste activated sludge (WAS). Therefore, this work aims to fill the knowledge gap through comprehensively investigating the effects of NGO on carbon transformation and methane production in the anaerobic digestion of WAS. Biochemical methane potential tests demonstrated the methane production dropped with increasing NGO additions, the cumulative methane production decreasing by 7.6% and 12.6% at the NGO dosing rates of 0.054 mg/mg-VS and 0.108 mg/mg-VS, respectively. Model-based analysis indicated NGO significantly reduced biochemical methane potential, with the highest biochemical methane potential decrease being approximately 10% at the highest NGO dosing rate. Further experimental analysis suggested that the decreased methane production was firstly related to a decrease in soluble organic substrates availability during the process of sludge disintegration, potentially attributing to the strong absorption of organic substrates by NGO. Secondly, NGO significantly inhibited the methanogenesis by negatively affecting the corresponding enzyme activity (i.e. coenzyme F420), which could also resulted in a decreased methane production.

Keywords: Anaerobic digestion; Biochemical methane potential; Methane production; Methanogenesis; Nano-graphene oxide; Waste activated sludge.