Biological remediation approach involving soils and groundwaters polluted with chlorinated solvents in a Mediterranean context

Abstract

Chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (PCE) form a class of dense non-aqueous phase liquid (DNAPL) compounds that cause a persistent environmental contamination that is difficult to investigate and challenging to remediate. The use of vegetation to enhance degradation by soil microorganisms of chlorinated solvents in soil-groundwater systems (phyto and rhizo-degradation) has been receiving attention since the 90¿ as an attractive low-cost alternative. Remediation strategies must be site-specific, with separate approaches often warranted for the DNAPL source zone and its associated aqueous phase plume. It has been suggested that possible mechanisms for the enhanced bioremediation of TCE in the rhizosphere are excretion of phenolic compounds in root exudates and plant mycorrhization.