Chromium (VI) pollution control in waste waters using new bio-sorbents

Author(s): V.Krishna Veni, K.Ravindhranath

Powders of leaves and their ashes of Ficus benghalensis, Syzygium cumini, Tamarindus indica, Acasia nilotica Indica, Acacia Arabica and Psidium guajava have been found to have strong affinity towards Chromium(VI) at low pH values. The sorption abilities of these bio-products in controlling the Chromium(VI) pollution inwastewaters have been studied with respect various physicochemical parameters such as pH, sorption concentration and equilibration time.%of removal of Chromium(VI) is pH sensitive and also depends on sorption concentration and time of equilibration. More than 90% of Chromium (VI) can be removed using these bio-sorbents at pH:2 and at optimumof equilibration time and sorbent concentrations. Cations even in ten fold excess are almost not interferingwith the extractability of Chromiumat the experimental conditions. Nitrate, Fluoride and Carbonate show seldom interference while sulphate and Phosphate are interfering to some extent in some sorbets and moreover even in these,%of extraction has never come down below 72.0%; Chloride except in the case of ashes of Acacia Arabica is not interfering. The adoptability of the methodologies developed is tested with some real industrial effluents and natural lake samples and found remarkably successful.

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