Risk assessment and technological options for contaminated sediments — a geochemical perspective

Abstract

The effective long-term remediation of contaminated sediments presents a particular challenge, since the large volume and the often diverse range of contaminants in these materials makes many of the traditional remediation techniques uneconomic. Future risk assessments of contaminated sediments should focus on assessing possible chemical changes in the stored sediment (e.g. redox changes and acid production) that could lead in the long term to contaminant remobilization. New biological criteria of contaminated sediments are also needed. These risk assessments must be undertaken with the potential remediation methods in mind. Priority needs to be given to the application of new geochemical engineering techniques, including chemical stabilization by additives and storage under permanent anoxic conditions, that optimize the long-term chemical stability of contaminated sediments.