Quantitative sustainability assessment of in situ thermally enhanced bioremediation for carbon efficient groundwater remediation

Abstract

In situ thermally enhanced bioremediation (ISTEB) is a promising approach for remediating contaminated soil and groundwater, yet comprehensive quantitative sustainability assessments of its sustainability remain scarce, especially for field-scale applications using hot water injection (TEB-HW) or thermal conductive heating (TEB-TCH). This study addressed this gap by developing the first fully quantitative sustainability framework integrating life cycle assessment (LCA) with best management practices (BMPs), comprising 108 indicators derived from extensive literature review and policy analysis. Using full-scale operational data from ISTEB implementations, we quantified the environmental, economic, and social performance of TEB-HW and TEB-TCH relative to conventional thermal treatment (TCH only). Results show that compared with TCH only, TEB-HW and TEB-TCH reduced carbon emissions by 78% and 31%, and achieved cost savings of 72% and 38%, while also improving community engagement and satisfaction. Normalized multi-criteria sustainability scores indicate overall performance gains of 31% and 13% compared to TCH only. Further optimization of BMPs, such as electric vehicle transport, green injectates, and renewable energy integration, could enhance ISTEB sustainability by up to 45%. These findings provide novel evidence for the practical viability and environmental benefits of ISTEB, offering actionable strategies for low-carbon, cost-effective, and socially acceptable remediation that align with sustainable production principles and contribute toward global net-zero carbon goals in contaminated site management.