Transport of Carbamazepine, Ciprofloxacin and Sulfamethoxazole in Activated Carbon: Solubility and Relationships between Structure and Diffusional Parameters

Abstract

The transport of carbamazepine, ciprofloxacin and sulfamethoxazole in the different pores of activated carbon in an aqueous solution is a dynamic process that is entirely dependent on the intrinsic parameters of these molecules and of the adsorbent. The macroscopic processes that take place are analyzed by interfacial diffusion and reaction models. Modeling of the experimental kinetic curves obtained following batch treatment of each solute at 2 µg/L in tap water showed (i) that the transport and sorption rates were controlled by external diffusion and intraparticle diffusion and (ii) that the effective diffusion coefficient for each solute, with the surface and pore diffusion coefficients, were linked by a linear relationship. A statistical analysis of the experimental data established correlations between the diffusional parameters and some geometrical parameters of these three molecules. Given the major discontinuities observed in the adsorption kinetics, the modeling of the experimental data required the use of traditional kinetic models, as well as a new kinetic model composed of the pseudo first or second order model and a sigmoidal expression. The predictions of this model were excellent. The solubility of each molecule below 60 °C was formulated by an empirical expression.

Removal of Organic Matter from Tunisian Industrial Phosphoric Acid by Adsorption onto Purified Natural Illite/Kaolinite Clay: Kinetics, Isothermal and Thermodynamic Studies

“…According to Weber and Morris [ 47 , 48 ], the adsorption of a fluid solute on the surface of the adsorbent occurs in four successive steps: Migration of the adsorbate from the bulk liquid phase to the boundary layer of the liquid film, which is bound to the solid particle. Transfer of the adsorbate through the liquid layer to the external surface of the adsorbent (external diffusion).…”

“…According to Weber and Morris [47,48], the adsorption of a fluid solute on the surface of the adsorbent occurs in four successive steps:…”

Ciprofloxacin and carbamazepine adsorption on activated carbons produced from leather residues

“…The adsorption capacity of WWAC presents a small variation (6%) with pH value. This behaviour was expected because CBZ is a neutral compound between pH 3 and 11 [22]. Nevertheless, for ROW_0.8 carbon the adsorption capacity is 30% higher at acidic pH, which may be a consequence of a poorer fitting of the model.…”

“…The highest adsorption capacities were obtained, for both materials, at acidic pH. CIP is an amphoteric compound and possesses both acidic and basic characteristics, and at acidic conditions (pH = 3) CIP is cationic [22]. The surface of activated carbons usually contains acid oxygen groups which can promote the adsorption of cations, explaining the higher adsorption capacities for acidic pH.…”

Retention of Ciprofloxacin and Carbamazepine from Aqueous Solutions Using Chitosan-Based Cryostructured Composites

“…On the other hand, some of the pharmaceuticals are persistent organic pollutants that cannot be eliminated by standard treatment facilities. One such example is the removal of carbamazepine (CBZ) through wastewater treatment facilities (WWTPs), which is typically less than 10% [ 16 , 17 , 18 ]. CBZ (or 5 H -dibenzo[ b,f ]azepine-5-carboxamide) is an effective drug often used for controlling epileptic seizures [ 19 ] or in the treatment of epilepsy and psychotropic activity [ 20 ].…”