Abstract:
Wastewater from rayon fiber manufacturing process contained high concentration of zinc has been treated using continuous current-controlling electrochemical method. Wastewater containing 155 ppm Zn2+ at pH 1.7 with 33.2 mS/cm conductance was used throughout these studies. An investigation begun with a reactor design. Reduction of KMnO4 were employed to indicate whether the reactor with or without salt bridge would provide a better result. Many materials made for salt bridge were also tested. Then, a reactor with sintered glass, as a salt bridge, was chosen for Zn removal process. Aluminum, iron, graphite and stainless steel were examined as a possibly cathode material to use for the Zn removal process. The pH and zinc concentration were monitored. From the results, a suitable electrode for the Zn removal using the controlled current current density method was stainless steel which could eliminate 98% of Zn within 30 min when 37.5 A/ m² current density was applied. A new aspect of adjusting controlled-current vs. time during the electrolysis course was proposed. It shows a benefit in less-time consuming in Zn removal process at great improvement in the current efficiency. The results revealed that 98% of Zn removal was achieved within 50 min electrolysis with 100% current efficiency at the highest.