SOIL WASHING POTENTIAL OF A NATURAL SURFACTANT

Biodegradable natural surfactants obtained from plants can be an attra ctive alternative to synthetic surfactants in the remediation of conta minated soils. In this research, a plant-based surfactant obtained fro m the fruit pericarp of Sapindus mukurossi, a tree generally grown in tropical regions of Asia, is tested. A simple and economical method fo r the preparation of the surfactant is developed. An empirical formula for the surfactant was determined to be (C26H31O10)(n). The aqueous s olubilities of hexachlorobenzene (HCB) and naphthalene in the natural surfactant solutions were found to vary linearly with the concentratio n of the surfactant showing trends comparable to that of typical comme rcial surfactants. Natural surfactant solutions were also employed for flushing HCB from one-dimensional soil columns. HCB recoveries after 12 pore volumes of flushing with 0.5 and 1% natural surfactant solutio ns were 20 and 100 times more than that recovered by water flooding. T hese promising results warrant further research to establish the usefu lness of plant-based surfactants for soil washing applications.