I. A. Amar; A. Sharif; M. M. Alkhayali; M. A. Jabji; F. Altohami; M. A. Abdul Qadir; M. M. Ahwidi
Abstract
In this study, the adsorption properties of spinel ferrite-based adsorbent, CoFe1.9Mo0.1O4 (CFMo), for removal of methylene blue (MB) from aqueous solution have been investigated. Sol-gel process was successfully employed to prepare CoFe1.9Mo0.1O4 magnetic nanoparticles. The synthesized adsorbent was ...
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In this study, the adsorption properties of spinel ferrite-based adsorbent, CoFe1.9Mo0.1O4 (CFMo), for removal of methylene blue (MB) from aqueous solution have been investigated. Sol-gel process was successfully employed to prepare CoFe1.9Mo0.1O4 magnetic nanoparticles. The synthesized adsorbent was characterized by Fourier transform infrared (FTIR), scanning electron microscope (SEM) and X-ray diffraction (XRD). The adsorption experiments were carried out at various operational conditions (solution pH, initial dye concentration, contact time, adsorbent dosage and temperature) to evaluate the potential adsorption property of CFMo magnetic nanoparticles. The results showed that, under the optimum adsorption parameters, approximately 95 % of MB dye can be removed. The adsorption data were better described by Langmuir isotherm model and the maximum amount of MB adsorbed was about 20.45 mg/g. Several adsorption kinetic models and thermodynamic parameters (∆Gº, ∆Hº, ∆Sº) were used to fit the adsorption experimental data. The adsorption kinetics followed the pseudo-second-order model (PSO), while the thermodynamic parameters indicate that the proposed adsorption process was endothermic and spontaneous in nature. The obtained results suggest that CFMo is promising adsorbent material for removal of very toxic dyes from aqueous solutions.
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..
S. N. Larimi; B. Ayati
Abstract
The present study used the adsorption process of activated carbon produced from agricultural wastes and the photocatalytic process of nano-ZnO to break down complex compounds available in removing Direct Blue 71 (henceforth, DB71). The two processes were done under three varied circumstances- adsorption/photocatalytic, ...
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The present study used the adsorption process of activated carbon produced from agricultural wastes and the photocatalytic process of nano-ZnO to break down complex compounds available in removing Direct Blue 71 (henceforth, DB71). The two processes were done under three varied circumstances- adsorption/photocatalytic, photocatalytic/ adsorption, and simultaneous use of the processes. First, DB71 was exposed to activated carbon produced from walnut and almond shells and the efficiency achieved at equilibrium time (45 and 60 minutes) was 55 and 60 percent, respectively. Then, DB71 was exposed to different dosages of nano-ZnO to remove the dye completely. The result showed that amount of AC/ZnO in an optimum condition for two walnut and almond shell absorbents were 0.75/0.096 and1/0.096 g/L. Second, (photocatalytic/ adsorption) the complex compound of DB71 with a dosage of 0.024 g/L was broken down as a result of UV radiation. The experiment proceeded with different dosages of walnut and almond shells after achieving the efficiency of 50% in removing DB71 in the second process. The amounts of AC/ZnO were 0.75/0.024 and 1/0.024 for walnut and almond shells respectively under the optimum condition for the second process. In the third process advantages of the simultaneous use of photocatalytic and adsorption processes were taken in which different dosages of AC/ ZnO were used. Given the smaller dosages of nano-ZnO and less dye removal time, amounts of 0.75/ 0.288 g/L and 0.75/0.288 g/L were measured for walnut and almond shells. The findings show that photocatalytic/adsorption process was the more optimal process because of the less dosages of nano-ZnO, efficiency of removing DB71 and shorter dye removing time. Furthermore, the effect of the intensity of UV radiant on the efficiency and time of removing DB71 was also examined. The experiment revealed that removing COD in the optimum conditions were 47.22 and 49.6 and 62.23 and 63.15 percent using walnut and almond shell respectively both in the first experiment and the simulations use of adsorption and photocatalytic processes after 30 hours. While, in the second experiment (photocatalytic/ adsorption) 42.21 and 39.18 percent of COD were removed using walnut and almond shell respectively after 30 hours. The LC-mass test of photocatalytic/adsorption process also showed the degradation of DB 71 complex compounds.
