Synthesis and characterization of chitosan-vermiculite-lignin ternary composite as an adsorbent for effective removal of uranyl ions from aqueous solution: Experimental and theoretical analyses.
Int J Biol Macromol 2022;
209:1234-1247. [PMID:
35461866 DOI:
10.1016/j.ijbiomac.2022.04.128]
[Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/08/2022] [Accepted: 04/17/2022] [Indexed: 12/25/2022]
Abstract
Chitosan (Ch), vermiculite (V) and lignin (L) were used as the components of a natural composite adsorbent (Ch-VL) for the removal of the UO22+ ions in aqueous solutions. During the study, we recorded and analyzed the initial UO22+ ion concentration, initial pH, contact time, temperature, and recovery. The recycling performance of the Ch-VL composite was assessed by three sequential adsorption/desorption experiments. Adsorption performance of the Ch-VL composite for UO22+ ions was 600 mg L-1 at pH 4.5 and temperature of 25 °C. Thermodynamic findings, ΔH0:28.1 kJ mol-1, and ΔG0:-14.1 kJ mol-1 showed that adsorption behavior was endothermic and spontaneous. Its maximum adsorption capacity was 0.322 mol kg-1, obtained from the Langmuir isotherm model. The adsorption kinetics indicated that it followed the pseudo-second-order and intraparticle diffusion rate kinetics. The adsorption thermodynamic shown indicated that the UO22+ ion adsorption was both spontaneous and endothermic. The adsorption process was enlightened by FT-IR and SEM-EDX analyses. The study suggested a simple and cost-effective approach for the removal of toxic UO22+ ions from wastewater. To highlight the adsorption mechanism, DFT calculations were performed. Theoretical results are in good agreement with experimental observations.
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