Abstract:
While various soil remediation technologies effectively mitigate environmental risks, they also incur substantial energy consumption and greenhouse gas (GHG) emissions. In this study, we performed a meta-analysis complemented by field-measured data to quantify the life-cycle carbon emissions of prevailing soil remediation technologies, and then evaluated the contribution of soil organic carbon (SOC) stock variations during remediation to GHG emissions. The results demonstrate that high-temperature, energy-intensive technologies–namely cement-kiln co-disposal, excavation and landfill, soil vapor extraction, and thermal desorption–exhibit the highest carbon emissions, averaging 207.85-270.64 kg/m
3 and reaching up to
1436 kg/m
3 under worst-case scenarios. In contrast, microbial and phytoremediation technologies demonstrate markedly lower average emissions of 44.69 and 39.17 kg/m
3, respectively, and in some cases, even below 3 kg/m
3, highlighting their low-carbon and environmentally sustainable nature. Intermediate technologies (e.g., chemical leaching and solidification/stabilization) produce average carbon emissions in the range of 64.42-175.19 kg/m
3. Additionally, changes in SOC during remediation are influenced by different technological approaches. Cement-kiln co-disposal, thermal desorption, electro-remediation, and chemical redox remediation all exhibit significant negative effects on SOC content (
P<0.05), while soil washing, microbial remediation, and solidification/stabilization technologies exert significant positive effects on SOC content (
P<0.05), with change rates of 18.2%, 35.5%, and 54.1%, respectively. This work pioneers the incorporation of SOC dynamics into the life cycle assessment (LCA) framework for contaminated soil remediation, systematically unraveling the emission profiles and decarbonization potentials of different soil remediation technologies. These findings advocate integrating GHG reduction metrics into technology selection and optimization processes, harmonizing pollution control with climate co-benefits, thereby providing quantitative support for policy formulation and engineering practice.