Recovering metal ions from oxalic acid leaching palygorskite-rich clay wastewater to fabricate layered mixed metal oxide/carbon composites for high-efficient removing Congo red. (March 2022)

• Record Type: Journal Article
• Authors: Lu, Yushen; Yu, Hui; Zhu, Yongfeng; Mu, Bin; Wang, Aiqin
• Is Part Of: Chemosphere. Volume 290(2022)
• Publication Date: 2022-03
• Subjects: Hydrotalcite-like composites -- Mixed metal oxide -- Carbon -- Adsorption -- Congo red; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.132543
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: This study developed a sustainable way to transform metallic residues in wastewater and spent adsorbents that adsorbed organic pollutants into novel high-efficiency adsorbents to treat water pollution again. The metal ions recovered from oxalic acid leaching palygorskite-rich clay wastewater was used to construct the hydrotalcite-like composites, after adsorbing organic pollutants, which was calcined and carbonized to convert into the mixed metal oxide/carbon composites (MMO/Cs). The fabricated MMO/Cs showed outstanding adsorption performance for the anionic azo dye Congo Red (CR). Especially, the MMO/C2 with the M 2+ /M 3+ molar ratio of 2, which adjusted by supplementing Mg 2+, had ultra-high adsorption capacity and ultra-clean removal efficiency for CR. The adsorption capacity was as high as 3303 mg/g, and only 0.5 g/L MMO/C2 dosing treatment for 6 h could completely decolor and remove the 2000 mg/L CR aqueous solution. Moreover, MMO/Cs exhibited the ability to simultaneous remove CR and Methylene blue (MB) mixed dye contaminants, and demonstrated the excellent recyclability. This work provides a promising method for the high-value conversion of waste resources and the synthesis of high-efficiency adsorbents. Graphical abstract: Image 1 Highlights: Sustainable transform metallic residues and spent adsorbents into efficient adsorbents. Recovered metal ions in OA leaching Pal-rich clay wastewater to fabricate LDHs. Transformed LDHs adsorbed CR solid waste into MMO/Cs to adsorption CR again. The adsorption capacity of MMO/C2 to CR is as high as 3303 mg/g. This way realized turning waste into treasure and treating waste with waste.