A comprehensive investigation of zeolite-rich tuff functionalized with 3-mercaptopropionic acid intercalated green rust for the efficient removal of HgII and CrVI in a binary system. (15th December 2022)

• Record Type: Journal Article
• Authors: Huang, Tao; Pan, Longwei; Dong, Jincheng; Zhou, Lulu; Tao, Hui; Zhang, Shu-wen; Li, Aiyin
• Is Part Of: Journal of environmental management. Volume 324(2022)
• Publication Date: 2022-12-15
• Subjects: Zeolite-rich tuff -- Sulfhydryl complexation -- Green rust -- Divalent mercury -- Hexavalent chromium -- Multi-mechanisms; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.116344
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: In this study, the 3-mercaptopropionic acid (MA) was chosen to achieve the anionic intercalation into the green rust (GR) materials (MA-GR). The zeolite-rich tuff functionalized with the MA-intercalated GR (MA-GR-tuff) was subsequently synthesized and used to remove both Hg II cations and Cr VI anions in a binary system. MA-GR-tuff showed the best adsorption capacities to both Hg II and Cr VI among the adsorbent materials. The optimal combination of parameters was determined as the molar ratio of Fe II to Fe III of 3.5, the molar ratio of OH − to the total iron of 3.75, the molar ratio of MA to the total iron of 2.5, and the mass ratio of the total iron to the tuff of 1.25. The pseudo-first-order kinetic model was appropriate in describing the kinetic sorption of Cr VI by MA-GR-tuff. Both the pseudo-first-order kinetic model and Elovich were suitable for explaining Hg II sorption. The maximum monolayer adsorption capacities of MA-GR-tuff towards Cr VI and Hg II were 185.19 mg/g and 72.99 mg/g, respectively. More flocs and plumes were formed in the MA-GR while the intercalation and more pores and crevices of different sizes were found in the MA-GR-tuff. Sulfhydryl complexation and the molecular sieve of tuff obviously both played a role in influencing the adsorption process. This study directly overcomes the drawback brought by the natural tuff to the treatment of a cationic-and-anionic binary system and supplies a new kind of tuff-based adsorbent for the potential use for the remediation of HM-contaminated wastewater. Graphical abstract: Image 1 Highlights: Anionic 3-mercaptopropionic acid was intercalated into the synthesis of green rust. Zeolite-rich tuff modified by MA-GR was used in a cationic-anionic binary system. Synthesis of MA-GR-tuff was optimized by desirability function and predictor. Hg II and Cr VI were dynamically adsorbed by MA-GR-tuff in multichannel pathways. This study solves the inefficiency of natural tuff to the binary HM contaminants.