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Comparison of synthetic surfactants and biosurfactants in enhancing biodegradation of polycyclic aromatic hydrocarbons
Author(s) -
Makkar Randhir S.,
Rockne Karl J.
Publication year - 2003
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/02-472
Subject(s) - bioremediation , bioavailability , biodegradation , chemistry , pulmonary surfactant , environmental chemistry , rhamnolipid , environmental remediation , polycyclic aromatic hydrocarbon , micelle , aqueous solution , contamination , organic chemistry , bacteria , ecology , bioinformatics , biochemistry , genetics , pseudomonas aeruginosa , biology
Polycyclic aromatic hydrocarbon (PAH) contamination of the environment represents a serious threat to the health of humans and ecosystems. Given the human health effects of PAHs, effective and cost‐competitive remediation technologies are required. Bioremediation has shown promise as a potentially effective and low‐cost treatment option, but concerns about the slow process rate and bioavailability limitations have hampered more widespread use of this technology. An option to enhance the bioavailability of PAHs is to add surfactants directly to soil in situ or ex situ in bioreactors. Surfactants increase the apparent solubility and desorption rate of the PAH to the aqueous phase. However, the results with some synthetic surfactants have shown that surfactant addition can actually inhibit PAH biodegradation via toxic interactions, stimulation of surfactant degraders, or sequestration of PAHs into surfactant micelles. Biosurfactants have been shown to have many of the positive effects of synthetic surfactants but without the drawbacks. They are biodegradable and nontoxic, and many biosurfactants do not produce true micelles, thus facilitating direct transfer of the surfactant‐associated PAH to bacteria. The results with biosurfactants to date are promising, but further research to elucidate surfactant–PAH interactions in aqueous environments is needed to lead to predictive, mechanistic models of biosurfactant‐enhanced PAH bioavailability and thus better bioremediation design.