Quantitative sustainability assessment for in-situ electrical resistance heating coupled with steam enhanced extraction: An effective approach for the development of green remediation technologies

Abstract

There is a lack of quantitative methodology for the sustainability assessment based on field data in the process of innovative technology development for groundwater remediation. This study developed a quantitative assessment framework, a model based on the life cycle assessment integrated with best management practices (LCA-BMPs), to evaluate the environmental, economic, and social sustainability of in-situ electrical resistance heating coupled with steam enhanced extraction (ERH-SEE), an innovative technology being demonstrated in the field. The results indicated that ERH-SEE offered better environmental sustainability performance compared to ERH only, with a reduction in carbon emissions by 52.6 %. ERH-SEE also significantly reduces human toxicity, resource consumption, and ecosystem impacts under the same remediation scenarios. The further assessment indicated that if taking the renewable energy share in energy structure in different countries into consideration, higher shares of renewable energy used in energy supplies can substantially reduce the environmental footprint of the studied scenarios. The economic sustainability assessment results showed that ERH-SEE was more sustainable than ERH only, as it reduces direct economic costs by 35.7 % and provides higher levels of worker employment. Regarding the social sustainability, ERH-SEE involved more complex operational procedures and presented more health risk exposure scenarios compared to ERH only, resulting in slightly more pronounced worker safety issues. Based on the final normalized results, the overall sustainability results of ERH-SEE and ERH only were 78.4 and 61.5, respectively, demonstrating that the sustainability performance of ERH-SEE was better than ERH only. It can be concluded that the application of ERH-SEE in groundwater remediation where significant heterogeneities occur in subsurface can increase the sustainability in developing countries, due to the lower percentage in renewable electricity in the energy supply. This study provided new insights into the technology development for the remediation of soil and groundwater contamination.