{"title":"Characterization and Adsorption Mechanism of Methylene Blue Dye by Mesoporous Activated Carbon Prepared from Rice Husks","authors":"Suchada Sawasdee, Prachart Watcharabundit","doi":"10.32526/ennrj/21/20230074","DOIUrl":null,"url":null,"abstract":"Environmental contamination due to synthetic dyes is a severe problem due to their adverse eco-toxicological effects. This study prepared activated carbon from H3PO4-activated rice husks (AC-RH) to adsorb methylene blue (MB) and predicted the adsorption mechanism. The AC-RH was characterized for N2 adsorption, surface functional groups, chemical compositions, and surface morphology. The activated carbon was classified to be a mesoporous material because 87% of its pore volume diameters are 3-50 nm. MB adsorption was studied under different conditions. Optimal MB adsorption occurred at pH 8, and the ideal equilibrium time was 360 min. The equilibrium adsorption was evaluated at concentrations of MB between 25 and 200 mg/L at 30°C. The Freundlich isotherm model matched the equilibrium data, and the greatest adsorption capacity of the Langmuir isotherm was 26.31 mg/g. The kinetic analysis revealed that the adsorption was pseudo-second-order, and its rate constant (k2) was higher at higher temperatures. For the thermodynamic adsorption study at 20 to 40°C, the Gibbs free energy (G) values were -6.291 to -9.197 kJ/mol, and the activation energy (Ea) was 26.248 kJ/mol: therefore, the methylene blue adsorption was spontaneous and physical. This study also revealed that the adsorption mechanisms were H-bonding, pore-filling, Yoshida H-bonding, n- interactions, electrostatic, and cation exchange.","PeriodicalId":11784,"journal":{"name":"Environment and Natural Resources Journal","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environment and Natural Resources Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.32526/ennrj/21/20230074","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Environmental Science","Score":null,"Total":0}
引用次数: 0
Abstract
Environmental contamination due to synthetic dyes is a severe problem due to their adverse eco-toxicological effects. This study prepared activated carbon from H3PO4-activated rice husks (AC-RH) to adsorb methylene blue (MB) and predicted the adsorption mechanism. The AC-RH was characterized for N2 adsorption, surface functional groups, chemical compositions, and surface morphology. The activated carbon was classified to be a mesoporous material because 87% of its pore volume diameters are 3-50 nm. MB adsorption was studied under different conditions. Optimal MB adsorption occurred at pH 8, and the ideal equilibrium time was 360 min. The equilibrium adsorption was evaluated at concentrations of MB between 25 and 200 mg/L at 30°C. The Freundlich isotherm model matched the equilibrium data, and the greatest adsorption capacity of the Langmuir isotherm was 26.31 mg/g. The kinetic analysis revealed that the adsorption was pseudo-second-order, and its rate constant (k2) was higher at higher temperatures. For the thermodynamic adsorption study at 20 to 40°C, the Gibbs free energy (G) values were -6.291 to -9.197 kJ/mol, and the activation energy (Ea) was 26.248 kJ/mol: therefore, the methylene blue adsorption was spontaneous and physical. This study also revealed that the adsorption mechanisms were H-bonding, pore-filling, Yoshida H-bonding, n- interactions, electrostatic, and cation exchange.
期刊介绍:
The Environment and Natural Resources Journal is a peer-reviewed journal, which provides insight scientific knowledge into the diverse dimensions of integrated environmental and natural resource management. The journal aims to provide a platform for exchange and distribution of the knowledge and cutting-edge research in the fields of environmental science and natural resource management to academicians, scientists and researchers. The journal accepts a varied array of manuscripts on all aspects of environmental science and natural resource management. The journal scope covers the integration of multidisciplinary sciences for prevention, control, treatment, environmental clean-up and restoration. The study of the existing or emerging problems of environment and natural resources in the region of Southeast Asia and the creation of novel knowledge and/or recommendations of mitigation measures for sustainable development policies are emphasized. The subject areas are diverse, but specific topics of interest include: -Biodiversity -Climate change -Detection and monitoring of polluted sources e.g., industry, mining -Disaster e.g., forest fire, flooding, earthquake, tsunami, or tidal wave -Ecological/Environmental modelling -Emerging contaminants/hazardous wastes investigation and remediation -Environmental dynamics e.g., coastal erosion, sea level rise -Environmental assessment tools, policy and management e.g., GIS, remote sensing, Environmental -Management System (EMS) -Environmental pollution and other novel solutions to pollution -Remediation technology of contaminated environments -Transboundary pollution -Waste and wastewater treatments and disposal technology