Removal of Chromium (VI) from Polluted Waters Using Biosorbents Derived from Some Herbal Plants

摘要

The sorption characteristics of powders of leaves ofAntigonan leptopus, Ipomoea cairica, Cleome viscosa L. for extracting Chromium (VI) from polluted waters have been studied with respect to various physicochemical parameters such as pH, sorption dosage and equilibrium time. The conditions for maximum removal of Chromium (VI) have been optimized. Tenfold excess of common cation ions present in natural waters, viz., Ca~(2+), Mg~(2+) ,Cu~2, Zn~(2+), Ni~(2+) and Fe~(2+) have synergistic effect in increasing the % removal of Chromium(VI). SO~(2-)_4, Phosphate and Carbonates are found to be interfering with the extractability of Chromium (VI) in the order: Phosphate > Sulphate> Carbonate. NO3-, Chloride and Fluorides have marginal interference. Maximum extractions to an extent of 96.0%, 92.0%, and 88.0% from synthetic waters are observed with the leaves powders of Antigonan leptopus, Ipomoea cairica, Cleome viscosa L. respectively atpH: 2 and at optimum equilibration time andsorbent concentrations. The methodologies developed are applied to diverse waste water samples collected from industrial effluents and polluted lakes. The procedures are found to be remarkably successful in removing the Chromium (VI) from waste waters.