O. Atamanova, E. Tikhomirova, M. Istrashkina, A. A. Podoksenov
{"title":"Study of mechanism of p-dinitrobenzene adsorption by modified bentonites when water purification in static conditions","authors":"O. Atamanova, E. Tikhomirova, M. Istrashkina, A. A. Podoksenov","doi":"10.23968/2305-3488.2020.25.2.3-11","DOIUrl":null,"url":null,"abstract":"Introduction. The paper provides a rationale for bentonite modification with organic substances to increase its adsorption capacity. The purpose of studying the adsorption mechanism of p-dinitrobenzene on bentonite modified by various methods is to determine such modifications of bentonite that allow for the most efficient removal of this toxic nitro compound from industrial wastewater. Methods. The authors analyzed four variants of bentonite adsorbent: unmodified granular bentonite; carbon nanotube (CNT) modified bentonite after heat treatment at 550 °C; glycerin modified bentonite after heat treatment at 550°C; glycerin and CNT modified bentonite after heat treatment at 550 °C. To determine the type of adsorption of p-dinitrobenzene on the studied sorption materials, the Dubinin– Radushkevich method was used. Results. Basic adsorption characteristics of the four indicated modifications of bentonite with respect to p-dinitrobenzene under static conditions were experimentally obtained. CNT modified bentonite showed the best adsorption characteristics: СОЕ = 1.56 mEq/g; Kd = 0.14 mg/dm3; S = 83.57 %. The constructed isotherms for adsorption of p-dinitrobenzene on modified and unmodified bentonites under static conditions confirmed that CNT modified bentonite after heat treatment at 550 °C has the best adsorption capacity. Unmodified bentonite showed the weakest adsorption capacity. The derived adsorption equations demonstrated that this process can be most accurately described by the Langmuir isotherm. With changes in the experimental temperature from 20 to 60 °C, the values of mean free energy E of adsorption of p-dinitrobenzene vary in the range of 11–20 kJ/mol. Thus, chemisorption is present in the process of adsorption of p-dinitrobenzene by the studied sorption materials.","PeriodicalId":38092,"journal":{"name":"Water and Ecology","volume":" ","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water and Ecology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.23968/2305-3488.2020.25.2.3-11","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: 1
Abstract
Introduction. The paper provides a rationale for bentonite modification with organic substances to increase its adsorption capacity. The purpose of studying the adsorption mechanism of p-dinitrobenzene on bentonite modified by various methods is to determine such modifications of bentonite that allow for the most efficient removal of this toxic nitro compound from industrial wastewater. Methods. The authors analyzed four variants of bentonite adsorbent: unmodified granular bentonite; carbon nanotube (CNT) modified bentonite after heat treatment at 550 °C; glycerin modified bentonite after heat treatment at 550°C; glycerin and CNT modified bentonite after heat treatment at 550 °C. To determine the type of adsorption of p-dinitrobenzene on the studied sorption materials, the Dubinin– Radushkevich method was used. Results. Basic adsorption characteristics of the four indicated modifications of bentonite with respect to p-dinitrobenzene under static conditions were experimentally obtained. CNT modified bentonite showed the best adsorption characteristics: СОЕ = 1.56 mEq/g; Kd = 0.14 mg/dm3; S = 83.57 %. The constructed isotherms for adsorption of p-dinitrobenzene on modified and unmodified bentonites under static conditions confirmed that CNT modified bentonite after heat treatment at 550 °C has the best adsorption capacity. Unmodified bentonite showed the weakest adsorption capacity. The derived adsorption equations demonstrated that this process can be most accurately described by the Langmuir isotherm. With changes in the experimental temperature from 20 to 60 °C, the values of mean free energy E of adsorption of p-dinitrobenzene vary in the range of 11–20 kJ/mol. Thus, chemisorption is present in the process of adsorption of p-dinitrobenzene by the studied sorption materials.
期刊介绍:
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