Potential for Phytoremediation of Contaminated Sediments

摘要

Phytoremediation is an innovative technology that is being applied to soil and groundwater cleanup. Techniques for using plants for remediation are gaining regulatory and commercial acceptance in the U.S. This paper considers the potential for application of phytore-mediation to the remediation of contaminated sediments, projecting from what is known about plant -contaminant mechanisms. The use of plants to remediate soil and groundwater problems has been studied for many years and is being applied nationally. Some of the mechanisms that have been identified may be applicable for use in sediments. Planting a contaminated sediment with shallow water wetland plants or deeper water emergent plants can form a vegetative root mass that acts as a cap to prevent movement of the sediment or contaminant while biore-mediation is occurring. A dense root mass not only holds existing sediments in place, it collects and gathers sediments that had been held in suspension, adding to the protective cap over the contamination. Vascular plants release oxygen and enzyme exudates from their roots. Some plants that grow in aquatic environments along streams, river banks, and in lakes may release enough oxygen and exudates into the subsurface sediments to promote contaminant degradation.