Life cycle assessment of bioslurry and bioelectrochemical processes for sustainable remediation of soil polluted with petroleum hydrocarbons: An experimental study

Bioremediation technologies have been widely used to clean up sites contaminated with various pollutants. Although these biological-based technologies may present a more sustainable appeal, the impacts they can pose on natural resources or climate change are rarely assessed. Hence in this study, the environmental performances of bioslurry and microbial electrochemical treatment (MET) are compared using a life cycle assessment method of SimaPro 9.1 software, and the primary environmental hotspots of the system and fifteen life cycle impact assessment options are evaluated using the ReCiPe 2016 characterization approach. The findings indicate that, compared to the bioslurry treatment, the MET approach is the most environmentally friendly choice since their value-added byproduct, the production of energy, offsets the environmental loads from the consequences that would have been averted. For up to 100 % of the impact category on global warming, environmental loads in both MET and bioslurry processes are dominated by biosurfactant production and electricity use. The system's environmental loads outweigh the impacts of the process by a factor of 1.6 for the global warming potential (GWP) due to the significant environmental gain from MET's energy output. Under every environmental impact category, the bioslurry process results in 100 times more environmental loads than MET. This study indicated that MET is an appropriate and feasible environmental remediation technology to support decision-making on the most suitable and least impactful strategy for cleaning contaminated sites. It also provides scientific references on the remediation of soil contaminated with petroleum hydrocarbons.