Effects of counterion type on selective arsenic removal process combining standard anion exchange resin with electrocoagulation for polluted groundwater. (20th January 2023)

• Record Type: Journal Article
• Authors: Li, Shida; Yang, Xiaoying; Wang, Zhixuan; Duan, Shoupeng; Zheng, Shaokui; Zheng, Xiangnan
• Is Part Of: Journal of cleaner production. Volume 385(2023)
• Publication Date: 2023-01-20
• Subjects: Arsenic -- Selective ion exchange -- Groundwater -- Electrocoagulation -- Coagulation; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.135762
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: This study achieved the highly selective removal of trace arsenic (As) from groundwater (110 μg L −1 As) by the standard anion exchange resin (AER) column process during long-term exhaustion–regeneration cyclic operation by optimizing the sulfate equivalent fraction (0.97 or 0.875) in sulfate-chloride or sulfate-bicarbonate binary brine (chloride or bicarbonate as counterion). No significant (<5%) or low (maximum: 25%) sulfate removal from the feedwater were stably observed during the 20 or 21 exhaustion–regeneration cycles without brine treatment or replacement, when <10 μg L −1 As was consistently observed in the product water. Furthermore, this study demonstrated the selective As removal from As-rich sulfate-chloride or sulfate-bicarbonate spent brine by aluminum (Al)- or iron (Fe)-based chemical coagulation or electrocoagulation process. Fe-based electrocoagulation (9-cm interelectrode distance, 0.50 mA cm −2, 15 min) and sulfate-chloride binary brine are finally recommended after metal dosage, sludge production and residual metal concentration among them were compared. No electrocoagulation took place in the sulfate-bicarbonate spent brine even at a current density of 3 mA cm −2 because of high bicarbonate concentration that formed passivation film on the anode surface. Finally, a combined process including a standard AER column and spent brine electrocoagulation was developed to achieve the stability and high As-selectivity of 114 exhaustion–regeneration cycles. Graphical abstract: Image 1