Calcium Sulfite Solids Activated by Iron for Enhancing As(III) Oxidation in Water

• Published in: Molecules (Basel, Switzerland) Switzerland), 2021-02, Vol.26 (4), p.1154
• Main Authors: Cai, Minjuan, Quan, Sen, Li, Jinjun, Wu, Feng, Mailhot, Gilles
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Arsenic; Arsenic - chemistry; Arsenic - isolation & purification; As(III); Calcium; Calcium - chemistry; CaSO3; Chemical Sciences; Communication; desulfurized gypsum; Efficiency; Experiments; Fe(III); Gypsum; Iron; Iron - chemistry; Kinetics; Liquid phases; or physical chemistry; Oxidation; Oxidation-Reduction; Pollutants; resource utilization; Soil conditioners; Sulfite; Sulfites - chemistry; Theoretical and; Water - chemistry; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Water Purification; Water treatment
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26041154

Desulfurized gypsum (DG) as a soil modifier imparts it with bulk solid sulfite. The Fe(III)-sulfite process in the liquid phase has shown great potential for the rapid removal of As(III), but the performance and mechanism of this process using DG as a sulfite source in aqueous solution remains unclear. In this work, employing solid CaSO as a source of SO , we have studied the effects of different conditions (e.g., pH, Fe dosage, sulfite dosage) on As(III) oxidation in the Fe(III)-CaSO system. The results show that 72.1% of As(III) was removed from solution by centrifugal treatment for 60 min at near-neutral pH. Quenching experiments have indicated that oxidation efficiencies of As(III) are due at 67.5% to HO , 17.5% to SO and 15% to SO . This finding may have promising implications in developing a new cost-effective technology for the treatment of arsenic-containing water using DG.