Decontamination of industrial effluents for environment protection and recycling of metals.

Preliminary results are presented of a low cost process dedicated to the decontamination of industrial effluents by chemically treated barks. Studies using solutions containing hexavalent chromium showed that the metal removal percentage depends on pH, initial concentrations and the tree species. More than 95% of Cr6+ contained in a 10, 100 or 1 000 ppm solution can be recovered at pH 3.80. The ashes obtained by the incineration of the saturated bark contain up to 50% of chromium metal which can be recycled by traditional metallurgical processes. Pilot plant trials were successful in eliminating about 90% of Cr6+ from industrial effluents containing about 5 000 ppm.
Preliminary results are presented of a low cost process dedicated to the decontamination of industrial effluents by chemically treated barks. Studies using solutions containing hexavalent chromium showed that the metal removal percentage depends on pH, initial concentrations and the tree species. More than 95% of Cr6+ contained in a 10, 100 or 1 000 ppm solution can be recovered at pH 3.80. The ashes obtained by the incineration of the saturated bark contain up to 50% of chromium metal which can be recycled by traditional metallurgical processes. Pilot plant trials were successful in eliminating about 90% of Cr6+ from industrial effluents containing about 5 000 ppm.