G L Dotto1, J M N Santos2, I L Rodrigues3, R Rosa4, F A Pavan5, E C Lima6. 1. Chemical Engineering Department, Federal University of Santa Maria, UFSM, Roraima Avenue, 1000, 97105-900 Santa Maria, RS, Brazil. Electronic address: guilherme_dotto@yahoo.com.br. 2. Chemical Engineering Department, Federal University of Santa Maria, UFSM, Roraima Avenue, 1000, 97105-900 Santa Maria, RS, Brazil. Electronic address: juhmnsantos@hotmail.com. 3. Chemical Engineering Department, Federal University of Santa Maria, UFSM, Roraima Avenue, 1000, 97105-900 Santa Maria, RS, Brazil. Electronic address: igor.rodrigues.mormon@gmail.com. 4. Chemical Engineering Department, Federal University of Santa Maria, UFSM, Roraima Avenue, 1000, 97105-900 Santa Maria, RS, Brazil. Electronic address: rejirr@hotmail.com. 5. Institute of Chemistry, Federal University of Pampa, UNIPAMPA, Bagé, RS, Brazil. Electronic address: flavio.pavan@unipampa.edu.br. 6. Institute of Chemistry, Federal University of Rio Grande do Sul, UFRGS, Porto Alegre, RS, Brazil. Electronic address: profederlima@gmail.com.
Abstract
HYPOTHESIS: Chitin is a biopolymer which can be used as a low-cost and eco-friendly material for dyes adsorption. The use of chitin for dyes removal is little investigated, due its low surface area, porosity and high crystallinity. So, an ultrasonic surface modified chitin (USM-chitin) was prepared and used for Methylene Blue (MB) adsorption. EXPERIMENTS: Chitin was obtained from shrimp wastes and its surface was modified by an ultrasound-assisted treatment. USM-chitin was characterized by N2 adsorption/desorption isotherms (BET surface area, total pore volume), infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The adsorption of MB on USM-chitin was studied by kinetic, equilibrium, thermodynamic, interactions analysis, desorption and mass transfer aspects. FINDINGS: USM-chitin presented surface area 25 times higher than raw chitin. The porosity was increased and the crystallinity was decreased. The general order model was suitable to represent the adsorption kinetics and the Langmuir model was adequate for the equilibrium. The maximum adsorption capacity was 26.69 mg g(-1). The adsorption was spontaneous, favorable and exothermic. USM-chitin can be used seven times maintaining the same adsorption capacity. Published by Elsevier Inc.
HYPOTHESIS: Chitin is a biopolymer which can be used as a low-cost and eco-friendly material for dyes adsorption. The use of chitin for dyes removal is little investigated, due its low surface area, porosity and high crystallinity. So, an ultrasonic surface modified chitin (USM-chitin) was prepared and used for Methylene Blue (MB) adsorption. EXPERIMENTS: Chitin was obtained from shrimp wastes and its surface was modified by an ultrasound-assisted treatment. USM-chitin was characterized by N2 adsorption/desorption isotherms (BET surface area, total pore volume), infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The adsorption of MB on USM-chitin was studied by kinetic, equilibrium, thermodynamic, interactions analysis, desorption and mass transfer aspects. FINDINGS:USM-chitin presented surface area 25 times higher than raw chitin. The porosity was increased and the crystallinity was decreased. The general order model was suitable to represent the adsorption kinetics and the Langmuir model was adequate for the equilibrium. The maximum adsorption capacity was 26.69 mg g(-1). The adsorption was spontaneous, favorable and exothermic. USM-chitin can be used seven times maintaining the same adsorption capacity. Published by Elsevier Inc.
Authors: Mariene R Cunha; Eder C Lima; Nilton F G M Cimirro; Pascal S Thue; Silvio L P Dias; Marcos A Gelesky; Guilherme L Dotto; Glaydson S Dos Reis; Flávio A Pavan Journal: Environ Sci Pollut Res Int Date: 2018-06-05 Impact factor: 4.223