Studies of Selective Adsorption Resins. XXII. Removal and Recovery of Arsenic Ion in Geothermal Power Waste Solution with Chelating Resin Containing Mercapto Groups

Abstract

Removal and recovery of harmful arsenic ion in a geothermal power waste solution with three macroreticular chelating resins containing mercapto groups were investigated. The resin (RES), which was prepared from 2,3-epithiopropyl methacrylate-divinylbenzene copolymer beads, exhibited high affinity for arsenic(III) ion and high resistance against hot water. In the column method, arsenic(III) ion in an aqueous solution was favorably adsorbed on the RES when the sodium arsenite solution (pH 6.2) containing 3 mg/dm³ of arsenic(III) ion was passed through the RES column at a space velocity of 15 h^?1. The arsenic(III) ion adsorbed was eluted by allowing 2 mol/dm³ sodium hydroxide solution containing 5% of sodium hydrogen sulfide to pass through the column. The recycle of adsorption and elution was found to be satisfactory. The RES also exhibited high adsorption ability for arsenic ion in the geothermal power waste solution.