Framework for determining optimal strategy for sustainable remediation of contaminated sediment: A case study in Northern Taiwan.

Contaminated sediment may pose a serious threat to human health and ecosystems. However, sediment remediation is typically an expensive and time-consuming process. Therefore, an effective decision-making process for the remediation of contaminated sediment is essential for identifying the optimal approach. Since a single assessment for sediment remediation may be insufficient, combining different analytical approaches is highly recommended. The objective of this study was to develop a comprehensive assessment framework based on the concept of green and sustainable remediation that considers various environmental, economic, and social aspects for the management of contaminated sediment. We propose a framework based on human health risk assessment (HHRA) and cost-benefit analysis (CBA) and apply the multicriteria decision analysis (MCDA) technique to implement integrated and sustainable strategies for sediment management. We used the framework to determine the best alternative for managing heavy-metal-contaminated sediment in a river in Northern Taiwan. The results of the pre-remediation HHRA indicated an unacceptably high cancer risk to children, while the CBA revealed that a remediation project was economically feasible. Moreover, the results of the MCDA revealed that a strategy involving in-situ capping with anthracite-based activated carbon would be relatively inexpensive and result in low risk to human health. In addition, this strategy would have a higher environmental impact and greater public acceptance as compared to a method involving the dredging and washing of soil. Thus, in this case study, in-situ capping using anthracite-based activated carbon was identified as the preferable remediation alternative from multiple perspectives. The proposed framework should allow decision-makers to choose the optimal integrated management strategy for similar river sites with contaminated sediment.