Adsorption of Chromium Ion by Acid Activated Low Cost Carbon‐Kinetic, Mechanistic, Thermodynamic and Equilibrium Studies

Abstract

A carbonaceous adsorbent prepared from an indigenous waste by acid treatment was tested for its efficiency in removing chromium ion. The parameters studied include agitation time, initial chromium ion concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intra-particle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm) obtained from the Langmuir isotherm plots were 27.40, 26.06, 26.06 and 26.17 mg/g respectively at an initial pH of 7.0 at 30, 40, 50 and 60°C. The temperature variation study showed that the chromium ion adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the chromium ion solutions. Almost 70% removal of chromium ion was observed at 60°C. The Langmuir and Freundlich isotherms obtained, positive ∆H0value, pH dependent results and desorption of dye in mineral acid suggest that the adsorption of chromium ion on PDC involves physisorption mechanism.

Nickel Ion Adsorption Behavior of Ceriporia lacerata Isolated from Mine Tailings in Korea

“…8). The value of R L (0.007) was observed to be in the range of 0 to 1, which confirms that the adsorption process was favorable (Arivoli et al, 2008).…”

Effect of Physical and Chemical Activation on the Removal of Hexavalent Chromium Ions Using Palm Tree Branches

“…The values of id and can be determined from the slope and intercept of the plot versus 1/2 and are listed in Table 3 ( Figure 6). Values of give an idea about the thickness of boundary layer; that is, the larger the intercept, the greater the contribution of the surface sorption in the rate controlling step [35]. Based on this plot (Figure 6), it was concluded that the sorption process of Cr(VI) is comprised of two phases, suggesting that intraparticle diffusion mechanism is not the rate limiting step for the whole reaction.…”

Sequestering of Fe and Pb ions from Wastewater by <i>Canarium schweinfurthii</i> after carbonization and chemical treatment: Isothermal and Kinetic Modeling

“…They also reported that as 1/n tends to zero, surface of adsorbent becomes more heterogeneous the influence of the ions on the surface of the adsorbent, making it more heterogeneous. Values of n obtained for all metal Arivoli et al (2005) reported that adsorption intensity (n) > 1 indicates the prevalence of chemisorptions over physical adsorption. K F value obtained for Fe (9.484 mg/g) for is greater than that of Pb (7.311mg/g).…”