Activated carbon obtained from bamboo waste was synthesised and modified with iron (BAC-Fe) and used for the removal of arsenic from aqueous solutions. Two different adsorption models were used for analysing the data. The adsorption capacities were determined for BAC-arsenite, BAC-Fe-arsenite, BAC-arsenate and BAC-Fe-arsenate, with a qmax (µg g−1) of 14.89, 19.19, 22.32 and 27.32 respectively. Adsorption capacity varied as a function of pH and modifications to the sorbent. Adsorption isotherms from an aqueous solution of arsenite and arsenates on activated carbons were determined. These adsorption isotherms were consistent with the Langmuir and Freundlich adsorption models. Adsorption kinetics followed a pseudo-first order rate equation, as did the kinetics for BAC-Fe-arsenite and BAC-Fe-arsenate adsorption. [...]
Competitive adsorption of zinc and copper on activated carbon is studied in this article. Main aim was to suggest an advanced model for competitive adsorption of both metals considering pH influence and precipitation. A surface-complexation approach was employed for the modeling. Two models were considered: simple adsorption and ion exchange. System “The Geochemists Workbench” was used for calculation of both static and dynamic adsorption tasks. From the batch experiments, concentration of four types of sorbing sites on the carbon surface and its protonation and sorption constants were deduced. Then, batch competitive adsorption experiments were compared with the models’ results. Finally, a column experiment (fixed bed adsorption) was carried out. It was observed that the model of ion exchange can satisfyingly predict both chromatographic effect and increase of zinc concentration in effluent over its initial value, although a quantitative agreement between the model and the experiment was not totally precise.
As metanil Yellow dye is removed from aqueous solution by batch adsorption on NATPAAC derived from G. aborea bark, we studied the effects of initial dye concentration (Co), initial pH and adsorbent dosage at 29 °C. The experimental equilibrium adsorption capacities (qe) obtained, were 2.35, 1.00 and 0.48 mg/g for Co 25, 50 and 100 mg/L, respectively. The kinetics and mechanism of the adsorption were then modeled by fitting experimental data into the pseudo-second order (PSO), Based on correlation coefficient R2 (> 0.95) values, results show that the PSO and Elovich models simulated experimental data well, but the PSO model simulated it the best. The Boyd model confirmed that the adsorption process was controlled by liquid film diffusion and the effective diffusion coefficients were very low. Moreover, the qe values decreased with increase in Co, increase in pH and increase in adsorbent dosage. However, the removal of MY from aqueous solution was very low. In addition, treatment of carbon with dilute HNO3 had no favorable impact.
Activated carbons containing different surface functionalities have been investigated as catalysts in conversion reactions of ethanol and methanol. These carbon materials were prepared from Polish brown coal by chemical activation with potassium hydroxide and modified by the oxidation or reaction with ammonia or chlorine. The main process upon ethanol decomposition was its dehydrogenation, while in the process of methanol decomposition only a few samples were catalytically active, and the only product was dimethyl ether (a product of dehydration). [...]
Two series of activated carbon have been prepared by chemical activation of Amygdalus Scoparia shell with phosphoric acid or zinc chloride for the removal of Pb(II) ions from aqueous solutions. Several methods were employed to characterize the active carbon produced. The surface area was calculated using the standard Brunauer-Emmet-Teller method. The microstructures of the resultant activated carbon were observed by scanning electron microscopy. The chemical composition of the surface resultant activated carbon was determined by Fourier transform infrared spectroscopy. In the batch tests, the effect of pH, initial concentration, and contact time on the adsorption were studied. The data were fitted with Langmuir and Freundlich equations to describe the equilibrium isotherms. The maximum adsorption capacity of Pb(II) on the resultant activated carbon was 36.63 mg g−1 with H3PO4 and 28.74 mg g−1 with ZnCl2. To regenerate the spent adsorbents, desorption experiments were performed using 0.25 mol L−1 HCl. Here we propose that the activated carbon produced from Amygdalus Scoparia shell is an alternative low-cost adsorbent for Pb(II) adsorption.
Activated carbon is a solid carbon compound that is composed of carbon in the form of charcoal. It plays a major role in some industrial applications such as water and air purification because of the strong adsorption of its surfaces and its tendency to remove some volatile organic compounds (VOC) and most of contaminants from the water, air or some other material. Various base materials are used in the manufacturing of activated carbon, including different woods and certain synthetic materials. According to the scope of new research, it is possible to produce activated carbon economically using coconut shell waste products. In our work, the coconut shells were burnt using a muffle furnace and at a range of temperatures in 300 ºC - 390 ºC. The elemental compositions of manufactured activated carbon were analyzed using X-ray fluorescence (XRF) spectrophotometer, while the surfaces of manufactured activated carbon were microscopically analyzed using an optical microscope. Thus, the range of 330 ºC - 350 ºC was considered as the most adequate temperatures for the manufacturing process of activated carbon from these coconut shells. Beyond the non-metal carbon, 68.85% Fe and 31.15% K are generated.
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