期刊名称：Journal of Materials and Environmental Science
印刷版ISSN：2028-2508
出版年度：2017
卷号：8
期号：9
页码：3397-3409
出版社：University of Mohammed Premier Oujda
摘要：The aim of this study is the valorization of fly ash, by-products of theJorfLasfar power plant in removing organic anionic dyes pollutants (indigo carmine and acid orange 52). The effects of contact time, pH and initial concentrations of the dyes, fly ash adsorbent dose and temperature on the removal of anionic dyes by fly ash were studied in batch mode. The removal of the two dyes (indigo carmine and acid orange 52) increases with the increase of contact time and dyes initial concentrations .Thus, the equilibrium adsorption capacity (qe) was increased with increasing contact time and initial dye concentration. The adsorption capacity of fly ash is independent of pH over the pH range 2-14. The results show that fly ash is an excellent adsorbent matrix. Indeed, for a fly ash concentration of 2.5 g/L, the dye removal percentages were 100% for indigo carmine dyeand 90% for the Acid Orange dye. Three kinetic models, pseudo first order, pseudo second order and the intra particle diffusion models were selected to study the adsorption process. The kinetic parameters, the rate constants, the equilibrium adsorption capacities and the correlation coefficients for each kinetic model were calculated and discussed. The best results were achieved with the pseudo second-order kinetic model. Experimental data were analyzed using the equations of Langmuir and Freundlich isotherm models. The best fit was obtained by the Langmuir isotherm model. The thermodynamic parameters, such as ΔH°, ΔS° and ΔG° were also experimentally determined. The adsorption kinetic mechanisms, and the substrate capacities are further discussed while correlated with the surface structure (XRD), composition (FX, FTIR), and morphology (SEM).The results indicate that the fly ash can be used as an efficient and low cost adsorbent for the removal of textile dyes from effluents. This work can help in designing low cost adsorption columns for treating effluent water in industries or other adsorption processes.
