Oxygen reduction on the surface of a rotating disk electrode RDE in 0.5 M H2SO4 is simulated by including mass transfer, adsorption, and charge transfer. A generalized model for the adsorption and reaction of several species is introduced. The oxygen reduction reaction is simulated as a limiting case where oxygen is the only species adsorbed, and oxygen reduction is the only reaction that takes...

Isotherms for the adsorption of KCl in PVOH-borate hydrogel was studied at 303 K by determining the amount of potassium and chloride ions adsorbed in PVOH-borate hydrogel using ion exchange chromatography and potentiometric titrations respectively. Experimental data was tested for Frendulich’s, Langmuir’s, Temkin’s and Dubinin–Radushkevich isotherms equations. The adsorption data follows isothe...

The adsorption of Triton X-100 in aqueous solution on the granite sand has been investigated to evaluate its ability as an adsorbent. Various parameters such as agitation time, adsorbent dose, adsorbent size, initial concentration of adsorbate, pH, temperature, and effect of interference ions were studied on the laboratory scale to establish optimum conditions for the removal of TX-100 from the...

This work aims to study the removal of Cu(II) and Cr(VI) from aqueous solutions with commercial coffee wastes. Materials with no further treatment such as coffee residues from café may act as adsorbents for the removal of Cu(II) and Cr(VI). Equilibrium data were successfully fitted to the Langmuir, Freundlich and Langmuir-Freundlich model (L-F). The maximum adsorption capacity of the coffee res...

In this work we have analyzed the adsorption-desorption kinetics in the framework of the lattice gas model. We have shown that the coefficients representing the transition probabilities must be carefully chosen even when they fulfill the principle of detailed balance, otherwise the observables arising from the kinetics present anomalous behavior. We have demonstrated that when the adsorption Ai...

The adsorption of contaminants plays an important role in the process of their elimination from a polluted environment. This work describes the issue of loading environment with lead Pb(II) and the resulting negative impact it has on plants and living organisms. It also focuses on bentonite as a natural adsorbent and on the adsorption process of Pb(II) ions on the mixture of bentonite and botto...

In this work, the removal of copper from an aqueous solution by granular activated carbon (GAC) in the presence of competitor ions was studied. A batch adsorption was carried out and different parameters such as pH, contact time, initial copper concentration and competitor ions concentration were changed to determine the optimum conditions for adsorption. The optimum pH required for maximum ads...

The adsorption of proteins and other large molecules at the liquid-solid interface often involves a surface-induced transition in either internal conformation or molecular orientation. Recently, Van Tassel et al. modeled this adsorption/transition process as the sequential surface placement of spreading disks. In this work, we employ the scaled particle theory (SPT) to derive approximate analyt...

A series of zwitterionic hybrid membranes were prepared via the ring opening of 1,3-propanesultone with the amine groups in the chains of TMSPEDA and a subsequent sol-gel process. Their kinetic models for strontium removal were investigated using three two-parameter kinetic equations (i.e., Lagergren pseudo-first order, pseudo-second order, and Elovich models). Adsorption mechanism was evaluate...

Application of activated carbon developed from rice husk, an agricultural waste product has been investigated for the removal of malachite green from aqueous solutions and wastewaters. Batch adsorption experiments were carried out for the removal of malachite green from aqueous solutions onto rice husk activated carbon. Effect of important parameters namely initial concentration of dye and cont...