PERFORMANCE AND CHEMICAL-STABILITY OF A NEW CLASS OF ETHOXYLATED SULFATE SURFACTANTS IN A SUBSURFACE REMEDIATION APPLICATION

The suitability of a surfactant for use in subsurface remediation depe nds on performance, toxicity and biodegradability. In order to increas e the performance of a series of edible, polyethoxylated sorbitol este rs, one or two sulfate groups were added to the hydrophilic poly(ethyl ene oxide) moieties. The solubilization and salt tolerance of these su rfactants were good, but they readily formed a mesophase when contacte d with a common soil at a high concentration. Crystals, which have the same maltese-cross patterns as liquid crystals, are also present when the mesophase forms. CMC of these surfactants are reported as well as soil adsorption and chlorinated organic solute solubilization data. T hese surfactants were found to undergo degradation at moderate tempera tures; a proposed mechanism for the breakdown and data on the rate of degradation are presented.