Effect of Sodium Dodecyl Sulfate on Phytoremediation of Phenanthrene and Pyrene by Siam Weed from Cadmium Co-contaminated Soils

Abstract

Co-contamination between polycyclic aromatic hydrocarbons (PAHs) and cadmium is important environmental problem and it is difficulty for phytoremediation of both contaminants. Use of synthetic surfactant is a one choice to increase the removal of both contaminants by phytoremediation. The aim of this study was to investigate the effect of SDS to stimulate the removal of phenanthrene, pyrene and cadmium from co-contaminated soil. In this study, SDS was added in soil contaminated with 204.5 mg/kg phenanthrene, 253.6 mg/kg pyrene and 81.0 mg/kg cadmium planted with Siam weed as 1x and 2x of critical micelle concentrations. SDS was added on day 53rd of experiment, soil and plant samples were collected on day 60th of the experiment. The results indicated that addition of SDS in soil did not stimulate the removal of phenanthrene and pyrene from soil. Amount of phenanthrene and pyrene remaining in planted soil were around 4.8-7.4 mg/kg, respectively. However, addition of SDS at 1x of critical micelle concentrations resulting in decreasing the amount of phenanthrene and pyrene removal from unplanted soil compared to unplanted soil without receiving SDS or receiving SDS at 2x of critical micelle concentrations. Also, SDS trend to increase phenanthrene accumulation in shoot of Siam weed more than pyrene but decreased cadmium accumulation in Siam weed shoot.