Treatment of Cyanide-Free Wastewater from Brass Electrodeposition with EDTA by Electrodialysis: Evaluation of Underlimiting and Overlimiting Operations

Autor(es)

Santana Barros, Kayo ^{[1, 2]} ; Scarazzato, Tatiana ^[3] ; Perez-Herranz, Valentin ^[2] ; Romano Espinosa, Denise Crocce ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Chem Engn, Av Prof Lineu Prestes, 580, Bloco 18, BR-05434070 Sao Paulo, SP - Brazil

^[2] Univ Politecn Valencia Spain, ISIRYM, IEC Grp, Cami Vera S-N, POB 22012, E-46022 Valencia - Spain

^[3] Fed Univ Rio Grande do SUl UFRGS, Dept Mat Engn, Av Bento Goncalves, BR-91501970 Porto Alegre, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MEMBRANES; v. 10, n. 4 APR 2020.
• Citações Web of Science: 0

Resumo

Growing environmental concerns have led to the development of cleaner processes, such as the substitution of cyanide in electroplating industries and changes in the treatment of wastewaters. Hence, we evaluated the treatment of cyanide-free wastewater from the brass electroplating industry with EDTA as a complexing agent by electrodialysis, aimed at recovering water and concentrated solutions for reuse. The electrodialysis tests were performed in underlimiting and overlimiting conditions. The results suggested that intense water dissociation occurred at the cathodic side of the commercial anion-exchange membrane (HDX) during the overlimiting test. Consequently, the pH reduction at this membrane may have led to the reaction of protons with complexes of EDTA-metals and insoluble species. This allowed the migration of free Cu2+ and Zn2+ to the cation-exchange membrane as a result of the intense electric field and electroconvection. These overlimiting phenomena accounted for the improvement of the percent extraction and percent concentration, since in the electrodialysis stack employed herein, the concentrate compartments of cationic and anionic species were connected to the same reservoir. Chronopotentiometric studies showed that electroconvective vortices minimized fouling/scaling at both membranes. The electrodialysis in the overlimiting condition seemed to be more advantageous due to water dissociation and electroconvection. (AU)

• Processo FAPESP: 12/51871-9 - Estudo de novas tecnologias e rotas de processamento para o tratamento e reciclagem de resíduos sólidos
• Beneficiário: Jorge Alberto Soares Tenório
• Modalidade de apoio: Auxílio à Pesquisa - Temático