Dr. Zainab Ziad Ismail
Abstract
Chromate plating activities are almost associated with certain amounts ofhazardous chromium wastes which might be considered as resource losses that can bedetoxified and recovered to ...
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Chromate plating activities are almost associated with certain amounts ofhazardous chromium wastes which might be considered as resource losses that can bedetoxified and recovered to usable product. The recycling of chromate from aqueouselectroplating sludge by oxidizing Cr (III) species to Cr (VI) form has been studied.Wet chemical oxidation was attempted with hydrogen peroxide to oxidize the Cr (III)contained in a freshly collected aqueous ferri-chromium hydroxide sludge in slightlyalkaline media (pH=8-9) at room temperature (25±5). Complete oxidation of Cr (III)with hydrogen peroxide could not be achieved. A maximum Cr (VI) recovery of only77% was obtained using 30.8 mm/l of Cr (III) as initial concentration initial. Theoxidation reaction kinetic was found to be dependent on trivalent chromiumconcentration and oxidant concentration which is described by the following rateequation:
