Comparative Study on the Adsorption Kinetics and Thermodynamics of Metal Ions onto Acid Activated Low Cost Pandanus Carbon

Batch experiments were carried out for the sorption of Copper and Ferrous ions onto acid activated carbon prepared. The operating variables studied were initial metal ion concentration, pH, and temperature and contact time. The equilibrium data were fitted to the Langmuir and Freundlich isotherm equations. From this adsorption efficiency, adsorption energy, adsorption capacity, intensity of adsorption and dimensionless separation factor were calculated. From the kinetic studies the rate constant values for the adsorption process was calculated. From the effect of temperature thermodynamic parameters like ΔG°, ΔH°, and ΔS° were calculated. The mechanism of adsorption for metal ions onto carbon was investigated by using the experimental results and confirmed by FT- IR, XRD and SEM images

Adsorption of Fe(II), Co(II), Ni(II) and Cu(II) ions onto a low cost activated carbon: Equilibrium, kinetic and thermodynamic studies

19-28Batch sorption system using activated carbon from Aegle marmelos fruits source as an adsorbent was investigated to remove Fe(II), Co(II), Ni(II) and Cu(II) ions from aqueous solutions. The system variables studied include initial concentration of the sorbate, agitation time, adsorbent dose, pH, co-ions and temperature. The experimental data fitted well to the Langmuir and Freundlich isotherms. The values of thermodynamic parameters such as ΔHº, ΔSº and ΔGº indicated that the adsorption was a spontaneous, endothermic and a physical process. Kinetic studies revealed that the adsorption is of first order. A two staged mechanism has been proposed for the adsorption of metal ions onto the adsorbent. FT-IR and SEM patterns of the adsorbent were used to understand the mechanism of the adsorption process. The order of adsorption of the metal ions was found to be Fe(II) > Cu(II) > Ni(II) > Co(II) which is in agreement with the intra-particle diffusion studies

Removal of basic and acidic dyes from aqueous solution by adsorption on a low cost activated carbon: Kinetic and thermodynamic study

130-139Batch experiments were carried out for the sorption of Congo red (CR), Malachite green (MG), Rhodamine B (RDB) and Rose Bengal (RB) dyes onto acid activated carbon prepared from a plant material, Aloe barbadensis Mill. The operating variables studied were initial dye concentration, pH, temperature and contact time. Equilibrium data were fitted to the Langmuir and Freundlich isotherm equations. From this, adsorption efficiency, adsorption energy, adsorption capacity, intensity of adsorption and dimensionless separation factor were calculated. The amounts of CR, MG, RDB and RB removed from a 60 mg L⁻¹ of the dye solution at 30ºC are 21.17, 26.19, 8.50 and 3.62 mg g⁻¹, respectively. The results of these studies indicate that the adsorption is favourable. From the kinetic studies, the rate constant values for the adsorption process were calculated. The thermodynamic parameters like ∆G°, ∆H°, and ∆S° indicate that the adsorption process is endothermic and spontaneous in nature. The mechanism of the adsorption of dyes onto the adsorbent has been investigated by using the experimental results and confirmed by FT IR, XRD and SEM images

Magnetoresistors based on magnetic composite materials

Describes a new type of magnetoresistor based on magnetic composite material. This device exhibits a magnetoresistance which is comparable to that of conventional magnetoresistors but can be realised with a very low cost technology. The theoretical analysis of the magnetoresistance characteristics of this device is also described

Magnetoresistors based on Composites

New magnetoresistor based on composite materials is proposed. This device exhibits characteristics comparable to those of conventional magnetoresistors but can be realized with much simpler technol

Adsorption of Malachite Green Dye by Acid Activated Carbon - Kinetic, Thermodynamic and Equilibrium Studies

The ability of zea mays dust carbon to remove malachite green from aqueous solutions has been studied for different adsorbate concentrations by varying the amount of adsorbent, temperature, pH and shaking time. Thermodynamic parameters such as ΔH°,ΔS° and ΔG°, were calculated from the slope and intercept of the linear plots. Analysis of adsorption results obtained at 303, 313, 323 and 333 K showed that the adsorption pattern on zea mays dust carbon seems to follow the Langmuir and Freundlich. The numerical values of sorption free energy indicate physical adsorption. The kinetic data indicated an intra-particle diffusion process with sorption being first order. The concentration of malachite green oxalate was measured before and after adsorption by using UV-visible spectrophotometer

Adsorption of Malachite Green Dye by Acid Activated Carbon - Kinetic, Thermodynamic and Equilibrium Studies

The ability of zea mays dust carbon to remove malachite green from aqueous solutions has been studied for different adsorbate concentrations by varying the amount of adsorbent, temperature, pH and shaking time. Thermodynamic parameters such as ΔH°,ΔS° and ΔG°, were calculated from the slope and intercept of the linear plots. Analysis of adsorption results obtained at 303, 313, 323 and 333 K showed that the adsorption pattern on zea mays dust carbon seems to follow the Langmuir and Freundlich. The numerical values of sorption free energy indicate physical adsorption. The kinetic data indicated an intra-particle diffusion process with sorption being first order. The concentration of malachite green oxalate was measured before and after adsorption by using UV-visible spectrophotometer