Chitosan-based composite microspheres for treatment of hexavalent chromium and EBBR from aqueous solution. (October 2022)

• Record Type: Journal Article
• Authors: Han, Shiqi; Zhou, Xuelei; Xie, Honghao; Wang, Xiaohong; Yang, Lingze; Wang, Huili; Hao, Chen
• Is Part Of: Chemosphere. Volume 305(2022)
• Publication Date: 2022-10
• Subjects: Microspheres -- Chitosan -- Adsorption -- Hexavalent chromium -- Pollution; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135486
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Hexavalent chromium is widely used in industrial fields, but its pollution has posed a great threat to the environment due to its high toxicity. We created a chitosan-based microsphere biosorbent (CP) by combining polyethyleneimine with chitosan adopting inverse emulsion polymerization method. Under the optimal conditions (pH = 3), the maximum adsorption capacity of composite microspheres can reach 299.89 mg g −1, which is much higher than that of chitosan microspheres (168.91 mg g −1 ). When the amount of CP is 0.25 g L −1, the removal rate of 50 mg L −1 Cr(VI) and 50 mg L −1 Eriochrome blue-black R (EBBR) can reach 95% and 99%, respectively. The time required for CP to reach adsorption equilibrium (180 min) was significantly shorter than that of chitosan microspheres (540 min), and the adsorption rate was significantly improved. Langmuir isotherm model, pseudo-second-order kinetic model and thermodynamic calculation results penetrated an endothermic spontaneous, monolayer, and chemical adsorption process. Biomass composite microspheres CP has obvious selectivity and the adsorption capacity retention rate of CP was still 71.32% after four adsorption cycles. This work proposed an easily prepared and biomass-based microspheres for the effective removal of Cr(VI) in printing and dyeing wastewater pollution through adsorption. Graphical abstract: Preparation of polyethyleneimine-grafted chitosan-based microsphere biosorbent and its adsorption performance for chromium(VI). Image 1 Highlights: A chitosan based microsphere (CP) was synthesized by inverse emulsion polymerization. The CP microsphere showed good adsorption properties for Cr(VI) and EBBR. The highly toxic Cr(VI) adsorbed on the surface of CP was reduced to less toxic Cr(III). CP microspheres can be reused many times when adsorbing Cr(VI) in solution.