To efficiently adsorb/separate or regenerate nickel ion, phosphoric acid, hypophosphorus acid and phosphorous acid remaining in liquid waste and/or washing water discharged from an electroless nickel plating bath.
The method for treating the liquid waste and/or washing water discharged from the electroless nickel plating bath comprises the steps of: adjusting the nickel ion concentration of the liquid waste and/or washing water discharged from the electroless nickel plating bath to ≤1,000 mg/L; adjusting the pH of the nickel ion concentration-adjusted liquid waste and/or washing water to 1-6; causing the pH-adjusted liquid waste and/or washing water to pass through a chelate resin to adsorb the nickel ion on the chelate resin; causing an acidic solution to pass through the nickel ion-adsorbed chelate resin to separate the nickel ion from phosphorus and recover the separated nickel ion; and, if necessary, subjecting the resulting liquid waste and/or washing water to flocculation/precipitation treatment to obtain nickel-containing valuable sludge.
COPYRIGHT: (C)2008,JPO&INPIT
TAWARA SHUNICHI
MATSUMOTO HIROMI
SHIMOJIMA YASUO
TSUKADA RIKEN KOGYO KK