Surfactant-assisted enhancement of bioremediation rate for hexavalent chromium by water extract of Sajina (Moringa oleifera) flower

The presence of hexavalent chromium in waste water is a serious environmental problem due to its toxicity and carcinogenicity. Bioremediation is an efficient alternative to the conventional chemical methods of treatment. Bioremediation of toxic hexavalent chromium is done by the reduction of hexavalent chromium to relatively less toxic trivalent chromium. In this study, water extract of Sajina flower, which contains different types of reducing components such as sugar, amino acid, is used as reductant and the rate of bioremediation is increased by treatment with anionic and neutral surfactants. Here surfactants are used as catalyst in the bioremediation process. Sodiumdodecyl sulfate (SDS) is found to be the best catalyst. In the absence of surfactants, 60.37% of the total chromium(VI) is reduced within 285 h, whereas the removal percentage increases up to 96.25 and 99.37% in the presence of TX-100 and SDS, respectively, in minimum time.