Overview of galvanic industries in Juazeiro do Norte, Brazil: emphasis on trace metal content in effluents and solid waste

Galvanic industrial effluents and wastes are a worldwide concern, as they contain highly toxic trace metals that are harmful to the environment and human health. This article presents an overview of the clad semi jewelry industry in Juazeiro do Norte, state of Ceara, Brazil, considering the production processes and the concentration of trace metals in the effluents and galvanic sludge waste generated by the sector. Primary production data were obtained from 11 companies by a technical questionnaire. Trace metal concentrations were obtained by flame atomic absorption spectrophotometry. The results showed inefficiency in the treatment of effluents for copper, nickel, chrome, lead, and zinc. The average metal concentrations in the galvanic sludge waste were 239 g Cu kg(-1), 99 g Zn kg(-1), 23.8 g Ni kg(-1), 6.6 g Pb kg(-1), 0.2 g Cr kg(-1), 1.7 g Cd kg(-1),1.0 g Mn kg(-1), and 8.2 g Fe kg(-1). The results evidenced the need for adopting measures concerning quality control of the effluent treatment processes aiming at the sustainability of the sector.