Abstract

Cyclodextrin-enhanced soil-remediation technologies
Éva Fenyvesi, Mónika Molnár, Laura Leitgib and Katalin Gruiz

Soil-remediation technologies that use cyclodextrins to enhance contaminant transport and availability are reviewed. The limited efficiency of soil-remediation technologies is caused by difficulties in effecting the transport of the contaminants. Transport can be enhanced by solubilizing agents, like surfactants and cyclodextrins, which improve desorption of the contaminants from the soil so that they can concentrate in the aqueous phase. As a consequence of the improved aqueous solubility, the KoCD values that have been introduced to characterize the partition between octanol and aqueous cyclodextrin solution are always lower than the Kow values.

In addition to soil washing, the processes of catalytic oxidation, electrokinetic remediation and permeable reactive barrier technology, as well as biological technologies (for example, phytoremediation and microbial degradation), can be intensified by using cyclodextrins as solubilizers. Compared with synthetic surfactants, the cyclodextrins are non-toxic and biodegradable; in fact their presence is actually beneficial to the soil biota. They can solubilize not only the contaminants (which provide substrates for the microbes) but also co-metabolites and organic nutrients. However, the risk of solubilizer-mediated enhancement of contaminant bioavailability is that non-target organisms may also suffer increased exposure to the contaminants.

Key words: bioavailability, bioremediation, electrokinetic remediation,  MOKKA, oxidation, permeable reactive barrier, phytoremediation, soil flushing, solubilizing agents

Land Contamination & Reclamation, 17 (3-4), 585-597 (2009)

DOI 10.2462/09670513.961

© EPP Publications Ltd 2009

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Article code 961