G. Ramezani; S. E. Moradi; M. Emadi
Abstract
Graphene oxide based nano-composites have attracted huge attention for wastewater treatment specially removal of heavy metals. This paper reports adsorption of onto modified magnetic graphene oxide with chitosan and cysteine (GO/ /Chi/Cys). To study the adsorbent morphology, Field Emission Scanning ...
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Graphene oxide based nano-composites have attracted huge attention for wastewater treatment specially removal of heavy metals. This paper reports adsorption of onto modified magnetic graphene oxide with chitosan and cysteine (GO/ /Chi/Cys). To study the adsorbent morphology, Field Emission Scanning Electron Microscope (FE-SEM) and Fourier Transform Infrared Spectrometer (FTIR) were used in different stages of surface modification. In order to reveal the nature of sorption process, linear forms of different adsorption isotherms such as Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich were studied. Experimental data were fitted well by Langmuir model with a maximum monolayer coverage capacity ( ) of 86.21 . Prediction of from Langmuir model was in good agreement with maximum empirical adsorption capacity ( =85.4 ). Various types of kinetic models such as pseudo-first-order, pseudo-second-order, Elovich, and intra particle diffusion were investigated to determine characteristic parameters in the adsorption process. The kinetic studies showed that pseudo-second-order model represents the adsorption process better than others due to its high correlation coefficient ( =0.9996). Therefore, the adsorption process is chemisorption.
M. El-khomri; N. El-messaoudi; S. Bentahar; A. Dbik; A. Lacherai
Abstract
In this work, Crystal Violet (CV), cationic dye, is removed from aqueous solution, using wood of Argan shell(ARS) and Almond shell (ALS), as low-cost and eco-friendly biosorbants. The parameters influencing the adsorption of CVon each of our adsorbents, contact time (5–180 min), adsorbent dose ...
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In this work, Crystal Violet (CV), cationic dye, is removed from aqueous solution, using wood of Argan shell(ARS) and Almond shell (ALS), as low-cost and eco-friendly biosorbants. The parameters influencing the adsorption of CVon each of our adsorbents, contact time (5–180 min), adsorbent dose (0.2–2 g), pH of the solution (3–11), temperature (20–50°C) and the initial dye concentration (50–500 mg.L-1), were studied.The modeling of experimental results obtained, shows that the CV adsorption on both biomaterials follows a pseudo-second-order kinetic and in perfect agreement with Langmuir isotherm. Also CV is better adsorbed on ALS that ARS, with maximum biosorption amounts 51.99 mg.g-1 and 37.32mg.g-1, respectively, at 40 ° C. Thermodynamic calculations have shown that the sorption is spontaneous, endothermic and random at the solid / solution interface. Adsorption capacities of dyes by ARS and ALS are better or comparable to those of several other biomaterials already studied.ALS and ARS biomaterials studied can be considered as alternative biosorbants low-cost and eco-friendly..