We report the density-functional calculations of NO2 adsorption on single-walled carbon nanotube walls. A single molecular adsorption was endothermic with an activation barrier, but a collective adsorption with several molecules became exothermic without an activation barrier. We find that NO2 adsorption is strongly electronic structure- and strain-dependent. The NO2 adsorption on metallic nano...

The contribution of variable grain sizes to uranium adsorption/desorption was studied using a sediment from the US DOE Hanford site. The sediment was wet sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.053-0.2 mm), and clay/silt fraction (<0.053 mm). For each size fraction and their composite (sediment), batch and flow-cell experiments were performed ...

a type of novel hypercross-linked fiber adsorbent was obtained by sulfonation and cross-linking reaction of polypropylene fiber grafted styrene-divinylbenzene. the aim of the fiber sulfonation and cross-linking method was to prepare rigid three dimensional networks in the entire fiber and change the ion exchange capacity of fiber. the hypercross-linked fiber adsorbent possesses a principally di...

Many important industrial separation processes based on adsorption operate close to saturation. In this regime, the underlying adsorption processes are mostly driven by entropic forces. At equilibrium, the entropy of adsorption is closely related to the enthalpy of adsorption. Thus, studying the behavior of the enthalpy of adsorption as a function of loading is fundamental to understanding sepa...

BACKGROUND In order to remove heavy metals, water treatment by adsorption of zeolite is gaining momentum due to low cost and good performance. In this research, the natural mordenite was used as an adsorbent to remove lead ions in an aqueous solution. METHODS The effects of adsorption temperature, time and initial concentration of lead on the adsorption yield were investigated. Response surfa...

the work focuses on the removing of cu(ii) from aqueous solution by linde f(k) zeolite. the zeolite is synthesized from fly ash by hydrothermal process. the adsorption experiments discuss several factors including the optimal solution ph, zeolite dosage, adsorption temperature, adsorption kinetics and adsorption isotherm equation. the results show that, the optimal solution ph is 6 and the effi...

The adsorption of polymers to surfaces is crucial for understanding many fundamental processes in nature. Recent experimental studies indicate that the adsorption dynamics is dominated by non-equilibrium effects. We investigate the adsorption of a single polymer of length N to a planar solid surface in the absence of hydrodynamic interactions. We find that for weak adsorption energies the adsor...

plants uptake boron (b) from the soil solution, in which boron concentration is controlled by adsorption and desorption reactions on soil organic and inorganic colloids. considering the importance of aluminosilicate minerals in ion adsorption and desorption reactions in soil, in this research, b adsorption behavior on kaolinite was studied as a function of equilibrium concentration, ph, kaolini...

Sodium pyrophosphate (pyro-P, Na4P2O7), sodium tripolyphosphate (tripoly-P, Na5P3O10), and sodium hexametaphosphate (meta-P, (NaPO3)6) were selected as the model compounds of condensed phosphate to investigate the adsorption behavior of condensed phosphate on aluminum hydroxide. The adsorption was found to be endothermic and divisible into two stages: (1) fast adsorption within 1 h; and (2) slo...

In this study the adsorption of Cu (II) ions from aqueous solutions on synthetic zeolite NaA was evaluated. The effect of solution temperature and the determination of the kinetic parameters of adsorption of Cu(II) from aqueous solution on zeolite NaA is important in understanding the adsorption mechanism. Variables of the system include adsorption time, temperature (293328K), initial solution ...