Two-scale evaluation of remediation technologies for a contaminated site by applying economic input-output life cycle assessment: risk-cost, risk-energy consumption and risk-CO2 emission

A two-scale evaluation concept of remediation technologies for a contaminated site was expanded by introducing life cycle costing (LCC) and economic input-output life cycle assessment (EIO-LCA). The expanded evaluation index, the rescue number for soil (RN_SOIL) with LCC and EIO-LCA, comprises two scales, such as risk-cost, risk-energy consumption or risk-CO₂ emission of a remediation. The effectiveness of RN_SOIL with LCC and EIO-LCA was examined in a typical contamination and remediation scenario in which dieldrin contaminated an agricultural field. Remediation was simulated using four technologies: disposal, high temperature thermal desorption, biopile and landfarming. Energy consumption and CO₂ emission were determined from a life cycle inventory analysis using monetary-based intensity based on an input-output table. The values of RN_SOIL based on risk-cost, risk-energy consumption and risk-CO₂ emission were calculated, and then rankings of the candidates were compiled according to RN_SOIL values. A comparison between three rankings showed the different ranking orders. The existence of differences in ranking order indicates that the scales would not have reciprocal compatibility for two-scale evaluation and that each scale should be used independently. The RN_SOIL with LCA will be helpful in selecting a technology, provided an appropriate scale is determined.