Environmental impact assessment and remediation decision-making of a contaminated megasite: Combining LCA and IO-LCA

Abstract

Environmental impact assessment is crucial for the green and sustainable development of contaminated sites. Although life cycle assessment (LCA) is a widely used quantitative approach for environmental impact assessment, its application in the context of megasite remediation is relatively limited and does not consider impacts on the entire industry chain. In this study, the LCA method and actual engineering data were used to carry out a detailed environmental impact assessment and decision-making on two remediation alternatives for a contaminated megasite in China. Subsequently, employing the input-output LCA (IO-LCA) method with Chinese local data and cost breakdown, a further environmental impact assessment of the selected alternative was performed. The findings revealed that Alt 1, which combined multiple remediation technologies, achieved a superior overall environmental impact score of 6.94 MPt compared to Alt 2, primarily based on landfill (score of 7.89 MPt). Despite the considerable uncertainty in the LCA results, Alt 1 had a 98.1% probability of outperforming Alt 2. In terms of the entire economic chain, the selected Alt 1 was estimated to emit 1.06 × 1010 kg CO2-eq, 6.06 × 106 kg of PM, 4.8 × 106 kg of NOx, 3.49 × 106 kg of SOx, 5.06 × 105 kg of COD, and 3.29 × 104 kg of NH3-N. The IO-LCA results indicated that LCA may substantially underestimated the environmental footprint of contaminated megasites remediation. This study provided valuable insight into the environmental assessment of contaminated megasites remediation and the selection and optimization of alternatives from a green and sustainable perspective.