Equilibrium and kinetics studies for the adsorption of direct and acid dyes from aqueous solution by soy meal hull
| Autor: | Mokhtar Arami, Nooshin Salman Tabrizi, Niyaz Mohammad Mahmoodi, Nargess Yousefi Limaee |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Langmuir
Time Factors Environmental Engineering Health Toxicology and Mutagenesis Water Purification chemistry.chemical_compound symbols.namesake Adsorption Desorption Spectroscopy Fourier Transform Infrared Environmental Chemistry Freundlich equation Coloring Agents Waste Management and Disposal Aqueous solution Chromatography Molecular Structure Langmuir adsorption model Sorption Hydrogen-Ion Concentration Pollution Solutions Kinetics chemistry Microscopy Electron Scanning symbols Soybeans Acids Acid dye Nuclear chemistry |
| Zdroj: | Journal of Hazardous Materials. 135:171-179 |
| ISSN: | 0304-3894 |
| DOI: | 10.1016/j.jhazmat.2005.11.044 |
| Popis: | This paper deals with the application of Soy Meal Hull (SMH), an agricultural by-product, for the removal of direct and acid dyes from aqueous solutions. Four textile dyes, C.I. Direct red 80 (DR80), C.I. Direct red 81 (DR81), C.I. Acid blue 92 (AB92) and C.I. Acid red 14 (AR14) were used as model compounds. Physical characteristics of SMH such as surface area, Fourier transform infra-red (FTIR) and scanning electron microscopy (SEM) were obtained. The surface area of SMH was found to be 0.7623 m(2)/g and the presence of functional groups such as hydroxyl, amine and carbonyl groups were detected. The effect of initial dye concentration, pH, contact time and SMH doses were elucidated at 20+/-1 degrees C. Results show that the pH value of 2 is favorable for the adsorption of all four dyes. The data evaluated for compliance with the Langmuir, Freundlich and BET isotherm models. It was found that data for DR80 and DR81 fitted well with Langmuir isotherm, for AB92, BET isotherm is preferred, while for AR14, the Freundlich isotherm is the most applicable. The adsorption capacities of SMH for DR80, DR81, AB92 and AR14 were, 178.57, 120.48, 114.94 and 109.89 mg/g of adsorbent, respectively. Also, adsorption kinetics of dyes was studied and the rates of sorption were found to conform to pseudo-second order kinetics with good correlation (R(2)> or =0.9977). Maximum desorption of > or =99.8% was achieved for DR80, DR81 and AB92 and 86% for AR14 in aqueous solution at pH 10. Based on the data of present investigation, one could conclude that the SMH being a natural, eco-friendly and low-cost adsorbent with relatively large adsorption capacity might be a suitable local alternative for elimination of dyes from colored aqueous solutions. |
| Databáze: | OpenAIRE |
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