Decontamination of solutions containing hexavalent chromium using modified barks.

Laboratory scale studies have been carried out of the decontamination of synthetic K2Cr2O7 solutions containing 10-1 000 ppm hexavalent chromium using chemically treated barks. A 2% pulp density in an agitated flask at optimum pH for two hours resulted in 95% chromium removal. Column percolation trials established the maximum retention times of the treated bark. Oak and pine bark had saturation rates of 110 and 215 mg Cr/g bark, respectively and incineration of the metal charged barks produced recyclable ashes containing 36 and 54% of Cr metal. Semi-pilot plant scale studies were carried out on Cr6+ removal from industrial effluents containing up to 1 800 ppm and about 90% of the Cr6+ was eliminated.
Laboratory scale studies have been carried out of the decontamination of synthetic K2Cr2O7 solutions containing 10-1 000 ppm hexavalent chromium using chemically treated barks. A 2% pulp density in an agitated flask at optimum pH for two hours resulted in 95% chromium removal. Column percolation trials established the maximum retention times of the treated bark. Oak and pine bark had saturation rates of 110 and 215 mg Cr/g bark, respectively and incineration of the metal charged barks produced recyclable ashes containing 36 and 54% of Cr metal. Semi-pilot plant scale studies were carried out on Cr6+ removal from industrial effluents containing up to 1 800 ppm and about 90% of the Cr6+ was eliminated.