'Remediability Score' as a tool for selecting the most suitable remediation technology for contaminated sites

Abstract

Land gets contaminated due to different human activities like illegal industrial discharges, mining activities, and spillage of chemicals. The pollutants released through these activities can have prolonged effects on the environment and human health. Therefore, there is a need for immediate remediation of the contaminated site. Different remediation technologies are available for remediating a land contaminated with a particular contaminant. Selection of the most appropriate remediation technology among all those available would help in quick and efficient remediation of the land. There are multiple factors deciding the appropriateness of a technology for a given case. 'Remediability' is a term introduced in the scientific literature recently to describe the ease with which a contaminated land can be remediated and 'Remediability Score (RS)' quantifies remediability in a 0-100 scale. The higher the value of RS, the greater is the difficulty for remediation. The factors influencing remediability were presented before a group of experts in a Delphi process for assigning comparative importance. From the importance score obtained in a Saaty scale of 1 to 9, the weights of factors were calculated using Fuzzy AHP. The overall RS was calculated by taking the weighted impact of the factors after their magnitudes were normalized. RS for the various remediation technologies feasible for a contaminated site, Kuzhikandam, near Kochi, Kerala was calculated. The site was revealed to be contaminated with heavy metals and organic compounds in a field investigation. The most suitable technology for remediating the selected site was found to be vitrification with an RS of 22. The next best technology, stabilization/solidification, had an RS of 25. The study showed that RS can be a reliable matric for selecting the most suitable remediation technology for a contaminated site.

Keywords: Environmental forensics; Fuzzy AHP; Remediability; Remediability Score; Remediation; Soil pollution.