Interaction of surfactants with organic contaminants in soil

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The normal use of surfactants in household products leads to their presence in domestic sewage and, for strongly adsorbing surfactants, in sewage sludge. Surfactants present in sewage sludge-amended soil have the opportunity to interact with other xenobiotics present in the soil such as chlorinated organics and polycyclic aromatic hydrocarbons.

The use of surfactants to decontaminate ground water aquifers and in soil clean-up operations is well established, and both anionic and nonionic surfactants have been used to remediate land polluted with oils and hydrocarbons as well as many other organic contaminants. In addition to soil cleansing properties, some surfactants, even at very low concentrations, have been shown to enhance the biodegradation of certain xenobiotics in soil.

However, at higher surfactant concentrations, it has been reported that degradation can be delayed due to the partitioning of xenobiotics into surfactant micelles. Surfactant: pollutant interactions in soil are very complex and depend heavily on a range of parameters including surfactant concentration in soil-water compared with critical micelle concentration (CMC), the adsorption characteristics of the surfactant and pollutant, solubility of the pollutant and the soil type.

The most important parameter in terms of the ability of a surfactant to mobilise hydrophobic xenobiotics in contaminated soil is the surfactant CMC. In general, concentrations of surfactant in soil-water below the CMC have little or no effect on solubilisation of hydrophobic materials. Only when micelles are present does significant desorption of such pollutants from soil surfaces occur.

  

Anabell Rose
Journal of Bioremediation & Biodegradation
Whatsapp NO.: +3228082557
bioremediation@escientificjournals.com