Adsorption characteristics of Fe(III) and Fe(III)–NTA complex on granular activated carbon

Synthesis, characterization and performance in arsenic removal of iron-doped activated carbons prepared by impregnation with Fe(III) and Fe(II)

“…3 shows the amount of iron inside the raw activated carbon after it was impregnated with solutions of FeCl 3 of various initial concentrations, either in 0.5 or in 3 M HCl. Just like in a previous work [45], the iron uptake increases with the initial concentration of the solution at a given fixed pH. Raw AC (and their oxidised counterparts N1-HH and N1-HO as well, see below), indeed has a low content of acidic surface groups, thus most of their Fe content after doping should originate from non-specific adsorption onto the surface.…”

Adsorption of Fe(III) from water by natural and acid activated clays: Studies on equilibrium isotherm, kinetics and thermodynamics of interactions

“…Very few reports exist that gives the values of the isotherm coefficients for adsorption of Fe(III). From his experiments on adsorption of Fe(III) on granular activated carbon, Kim (2004) has reported adsorption isotherms giving good fit of the Freundlich equation (r 2 = 0.9468) with values of adsorption capacity (K f ) and adsorption intensity (n) as 0.108 and 0.423. The results obtained in the present work are reasonably better compared to this.…”

“…It has been known that the stability of the hydrated hydroxide ion in aqueous solution is less than that of the hydrogen ion. This is due to the fact that the hydroxide ion is larger than the proton, and therefore, more water molecules are required to surround this ion for hydration (Shaw, 1980;Kim, 2004). This results adsorption of much more OH − ions on clay compared to H + ions.…”

Biosorption of Astrazone Blue basic dye from an aqueous solution using dried biomass of Baker's yeast

“…This suggests that the chemical bonds between the yeast surface and the dye molecules are strong enough and the dye molecules cannot be easily desorbed by physical means such as simple shaking or heating [25]. Also the positive value of H implies that the adsorption reaction of Astrazone Blue (F2RL 200%) onto Baker's yeast is endothermic [32]. The increase in adsorption of dye with temperature may be due to dissolution of the adsorbing species, changes in the pores sizes of adsorbents and enhanced rate of intra-particle diffusion.…”