Remoção e proposta de reutilização do cromo contido no banho de curtimento por via de um processo eletroquímico.

Abstract

A major problem of the chemical such as mineral processing, electroplating, tanning and extractive metallurgy is the high toxicity of their effluents, which contain heavy metals such as copper, lead, zinc, chromium and others. The treatment of these effluents have been intensified by issues of economic and environmental order. The conventional treatment of effluents from industry and processing of leather pelts is not always effective and some parameters, such as the concentration of total chromium, among others, finds it very difficult to achieve the release pattern established by the law, it becomes increasingly rigid with a view to environmental protection. This work aimed to study the feasibility of applying the electrochemical process, electroplating, chromium contained in the removal of the residual tanning bath. Assays were performed in a reactor-scale film descendant semipiloto. The anode plate used was a DSA ® expanded as a cathode and a planar plate of stainless steel. The synthetic wastewater used was similar to that used in CTCC (Technology Center of Leather and Footwear Albano Franco - Campina Grande - PB). Under the conditions of this work, the maximum removal of 31.28% was obtained at 2.0 hours of electrolysis current density of 150 A.m-2 and feed flow rate of 420 L.h-1. A correlation was also achieved using the methodology of the π-Buckingham Theorem who represented the mass transport mechanism for removal of chromium ions from wastewater. The mass transfer coefficients were obtained by the method used in the voltammetric electroreduction of potassium ferricyanide (Fe (CN)6K3) under control diffusion. The performance indicators of the reactor of this study showed that this competitive shown, however, requiring optimization system and process of moving chromium.