Redução eletroquímica do cromo VI - utilização do feltro de grafite RVG - 4000 como eletrodo de trabalho.

Abstract

Heavy metals in industrial waste constitute environmental and health risks even in a very low concentration. The U.S. Department of Health and Human Services has determined that chromium compounds are known carcinogens with only 0,05 ppm being acceptable in drinking water. The objective of this work was the study of electrochemical reduction of hexavalent chromium Cr(VI) to Cr(III) ions from a dilute synthetic solution of K2Cr207 and Na2SO4(0,05 N). A graphite felt, RVG 4000 ( Le Carbone Lorraine, France) was used as work electrode in a flow - by reacts. Its morphological characteristics such as its specific surface, porosity, average fibre diameter and permeability were determined. The influence of some perametus offecting the process selectivity such as initial concentration of Cr(VI), solution pH, current intensity and cell voltage on the concentration - time relationship and conversion yield are considered. Some kinectics aspects was studieds.