Effect of reactive mats on in-situ remediation of contaminated marine sediment

The management and treatment of contaminated sediment is a considerable environmental issue recognized worldwide, that poses major technical and economic challenges. Nowadays, there is an acute need for remedial technologies that can address both a variety of contaminants in a range of aquatic environments and provide permanent solutions by reducing contaminant toxicity. Among the remediation options, In Situ Capping (ISC) turns out to be a less expensive and disruptive, and more durable approach. However, by using low adsorption capacity materials, passive caps do not always fulfil the reduction of risks. Further alternative called active capping involves the use of chemically reactive materials (i.e., activated carbon, apatite, zeolite, organoclay) that sequestrate and/or degrade sediment contaminants in order to reduce their mobility, toxicity, and bioavailability. This study provides a review on the types of active materials tested in recent active capping studies. A special focus was devoted to reactive mat: It is a new class of in situ sediment remediation technique consisting of a reactive layer containing one or more neutralizing or otherwise reactive materials that is confined between two permeable geotextile layers.