Removal of Chromium and Organic Pollutants from Industrial Chrome Tanning Effluents by Electrocoagulation |
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| Authors: | A K Golder A N Samanta S Ray |
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| Affiliation: | 1. Indian Institute of Technology Guwahati, Department of Chemical Engineering, Guwahati, India;2. Indian Institute of Technology Kharagpur, Department of Chemical Engineering, Kharagpur, India |
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| Abstract: | The treatment of industrial chrome tanning effluents by electrocoagulation (EC) in a laboratory‐scale reactor was investigated. Mild‐steel (MS) electrodes have been found to outperform aluminum (Al) electrodes in reducing the Cr(III) concentration to <2 mg L–1. The conversion of Fe(II) to Fe(III) is slow in the lower pH range (<6), and OH– ions generated during EC are amply available for Cr(III) removal by precipitation in the case of the MS electrode. Formation of Al(OH)3(s) in competition with Cr(OH)3(s) while consuming the OH– ion is a cause for lower Cr(III) removal with Al. EC with the MS electrode and chemical coagulation (CC) with addition of alkali proved to be equally efficient for removing Cr(III). |
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| Keywords: | Biochemical oxygen demand Chemical coagulation Chemical oxygen demand Chrome tanning effluent Electrocoagulation Hydroxide precipitation |
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