Quantitative sustainability assessment and application of remediation technologies for heavy metal-contaminated sites based on multi-criteria decision-making method

To address the lack of comprehensiveness and specificity in existing sustainability assessment systems for heavy metal contaminated site remediation, this study proposes a decision-making method based on the AHP-MOGA-CS-TOPSIS coupling model. The sustainability assessment of heavy metal-contaminated site remediation technologies is based on four types of indicators, namely, environmental (EN), economic (EC), social (SO), and effective (EF). The technique for order preference by similarity to ideal solution (TOPSIS) is innovatively applied to prioritize the alternatives by combining Analytical Hierarchy Process (AHP), Cosine Similarity (CS), and Multi-objective Genetic Algorithm (MOGA). In order to validate the methodology, three techniques [Cement Kiln Co-processing (CKC), Situ Ectopic-chemical Washing (ICW), and Situ Ectopic-chemical Stabilization (ICS)] were investigated. Sustainability scores were 0.76, 0.84, and 0.64, respectively. The uncertainty and sensitivity results showed that the proposed methodology is feasible for stakeholders and decision-makers considering the remediation of heavy metal-contaminated sites. The cases show that ICS is the most sustainable remediation option, and ICS has the lowest carbon emissions (1.52×10^7 kg CO 2 eq ); thus, ICS has the best sustainability and the lowest carbon emission. The correlation between carbon emissions and sustainability results was 0.84, and although carbon emissions do not fully describe the sustainability of restoration techniques, they can indicate the sustainability ranking of remediation techniques. This study provides new insights for the sustainable remediation of heavy metal-contaminated sites and synergize with the dual carbon goals. • Remediation effective was covered in the assessment indicators system. • A sustainability assessment indicators system for HM-contaminated soil was developed. • A sustainability assessment framework AHP-MOGA-CS-TOPSIS model was established. • In situ ectopic-chemical stabilization is sustainability in typical remediation case.