A continuous process in mixers-settlers for the removal/recovery of chromium in effluents from the tanning industry.

One of the main environmental issues caused by the tanning industry is given by the high concentration of chromium contained on its effluents. The removal of this pollutant has become a technological challenge. To solve this issue, this work proposes a continuous process based on mixers-settlers for the removal of the chromium present in effluents from the tanning industry.

Electrocoagulation treatment of industrial tannery wastewater employing a modified rotating cylinder electrode reactor.

The removal of highly concentrated pollutants, presented in a wastewater mixture from industrial tannery effluents by electrocoagulation, was examined. All experiments were carried out in a rotating cylinder electrode reactor with six aluminum anodes and two sedimentation tanks. The influence of the applied current density and rotational speed on the removal efficiency of an electrocoagulation reactor was studied.

Aerobic processes for bioleaching manganese and silver using microorganisms indigenous to mine tailings.

Mining wastes containing appreciable concentrations of silver are considered alternative sources for metal extraction, although these wastes are often refractory due to the presence of manganese oxides. The high cost and/or environmental impact of the hydrometallurgical and pyrometallurgical extraction processes make it necessary to search for biotechnological processes for the solubilization of manganese compounds. This paper describes the characterization of chemoorganotrophic microorganisms indigenous to the tailings of a silver mine located in Coahuila, México, regarding their capability to remove manganese and silver present in these residues by lixiviation.