Evaluation of the efficacy of halloysite nanotubes in the removal of acidic and basic dyes from aqueous solution
| Autor: | Arjun Maity, Vhahangwele Masindi, Jabulani Ray Gumbo, Tholiso Ngulube |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Aqueous solution
Chemistry 020101 civil engineering 02 engineering and technology engineering.material 010502 geochemistry & geophysics 01 natural sciences Chemical reaction Halloysite 0201 civil engineering Gibbs free energy chemistry.chemical_compound symbols.namesake Adsorption Chemical engineering Geochemistry and Petrology Methyl orange engineering symbols Crystal violet Methylene blue 0105 earth and related environmental sciences |
| Zdroj: | Clay Minerals. 54:197-207 |
| ISSN: | 1471-8030 0009-8558 |
| Popis: | The present work describes the removal of Direct Red 81, Methyl Orange, Methylene Blue and Crystal Violet from aqueous solution using halloysite nanotubes. The clay mineral was physicochemically characterized using various methods. The influences of pH, interaction time, initial dye concentration, adsorbent amount and temperature on adsorption were monitored and interpreted. Although previous work has shown that acidic pH conditions favour the adsorption of pollutants from aqueous systems by clay materials, in this study maximum removal was possible over a wide range of pH conditions (pH ≥2–12). Adsorption was very rapid, and equilibrium was attained within 30 min. For all four dyes studied, chemical reaction seemed significant in the rate-controlling step, and the pseudo-second-order chemical reaction kinetics provided the best correlation of the experimental data. Thermodynamically, the process was spontaneous, with Gibbs energy decreasing with increasing temperature. Halloysite would be suitable for removing dyes from aqueous solution. This was further tested by using the halloysite nanotubes for the removal of complex dyes from printing and ink industry effluents. |
| Databáze: | OpenAIRE |
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