Recycling of Wastewater for Electroless Nickel Plating by Deionization with Ion Exchange Resin and Reverse Osmosis Membrane after Oxidation with Fenton's Reagent

Abstract

For recycling, waste rinse water from electroless nickel plating is oxidized with a hydrogen peroxide (H₂O₂) -iron (II) ion system, known as Fenton's reagent, and treated followed by coagulation with reuse of Fe3+ ions oxidized by H₂O₂. The oxidized solution was desalinated with a reverse osmosis (RO)membrane. It was then passed through a cation exchange resin column and an anion exchange resin column in series. The coagulation after oxidation decreased COD, nickel ion, SiO₂, and suspended solid matter well.
Water deionized by the ion exchange method after desalting with an RO membrane can be reused in the final rinsing process. The electric conductivity of permeated water from the RO membrane did not exceed 13 mS/m and effluent from the anion exchange column was less than 1 mS/m.
Based on the present experimental results, we derived a practical wastewater recycling system for electroless nickel plating. This recycling technique has enabled the reuse of wastewater for electroless nickel as deionized water for the final rinsing process.