Aspects Of Sorption Research Articles

Magnetic hybrid nanoparticles modified with morin for the removal of Sc(III) from aqueous solutions

In this research magnetic hybrid nanomaterials modified with morin for sorption of scandium ions have been synthesized and investigated. In general, sorption of scandium increases with increasing pH. However, Fe@COO-morin nanocomposite with covalently bonded morin showed superiority over physically coated Fe3O4@morin nanoparticles. Several models have been applied for investigation of different aspects of sorption onto Fe@COO-morin. Results show, that it follows Langmuir model and pseudo-second order kinetics. Developed hybrid Fe@COO-morin nanoparticles were successfully applied for separation and preconcentration of scandium using magnetic solid phase extraction from spiked water samples. Optimized procedure includes selective sorption of scandium at pH 5, elution with 1 mol L−1 HNO3 and ICP OES determination. A preconcentration factor of 20 was achieved and sorbent provides the possibility of multiple use.

Sorption Extraction of Rare Earth Metals from Wet-Process Phosphoric Acid

When apatites and phosphorites are processed, up to 30% of rare earth metals are converted into wet-process phosphoric acid. Wet-process phosphoric acid from the phosphorite treatment process differs from apatite one by impurity composition, i.e. the iron content is by 3.5 times, and calcium is by 5.0 times more. The complex composition of the wet-process phosphoric acid from the phosphorite treatment process requires additional researches to select optimal ion exchangers and technological parameters of sorption. Various aspects of sorption have been studied to select the optimal ion exchangers and technological parameters, and technological modes for desorption of rare earth metals from a cation exchanger to obtain a concentrate of rare earth metals have been completed. The method enables to extract rare earth metals without changing the composition of commercial wet-process phosphoric acid directly in the production process of the enterprises engaged in the phosphorite treatment process.

Fundamental aspects of sorption of copper ions by aminohydroxyl-containing fibrous complexite

Fundamental aspects of sorption of copper ions by a complexite based on an aminohydroxyl-containing grafted copolymer of polycaproamide and poly(glycidyl methacrylate) were studied. The main kinetic and capacity parameters of the sorption process were determined. The possibility of reaching a high degree of recovery of copper ions from low-concentration solutions was demonstrated.

Aspects of sorption and phase behavior of near-critical fluids confined to mesoporous media

The local structure of a Lennard-Jones fluid confined to a mesoscopic slit-pore with structureless (i.e., “smooth”) walls is investigated by computing the local density ρ(z) in grand canonical ensemble Monte Carlo (GCEMC) simulations. For noncritical thermodynamic states of a corresponding bulk fluid, a homogeneous core region exists in the pore characterized by the bulk density ρbulk. Sufficiently close to the bulk critical point, however, the core is depleted, that is its local density ρcore(z) is less than ρbulk. Along a bulk near-critical isotherm T*=1.36≃Tc,bulk* GCEMC data are analyzed in terms of the equations of state μbulk=μ(ρbulk,Tc,bulk) and μcore=μ(ρ̄mid,Tc,bulk), respectively, where ρ̄mid is the average midpoint density of the core fluid. At densities sufficiently above and below the bulk critical density thermodynamic states of core and bulk are the same, i.e. μbulk=μcore. However, if depletion is observed the density dependence of μbulk and μcore is generally different. By applying a mean-field theory to μbulk and μcore depletion is related to a reduced degree of criticality of the core fluid compared with the bulk phase in a self-contained way.