A reversible adsorption-desorption parking process in one dimension is studied. An exact solution for the equilibrium properties is obtained. The coverage near saturation depends logarithmically on the ratio between the adsorption rate, k + , and the desorption rate, k − , ρ eq ∼ = 1 − 1/ log(k + /k −), when k + /k − ≫ 1. A time dependent version of the reversible problem with immediate adsorpt...

Pesticide sorption in soils is controlled by time-dependent processes such as diffusion into soil aggregates and microscopic sorbent particles. This study examines the rate-controlling step for time-dependent sorption in clay loam aggregates. Aggregates (5 mm) were stabilized with alginate, and adsorption of azoxystrobin, chlorotoluron, and cyanazine was measured in batch systems equilibrated f...

The adsorbents of starch grafted p-tert-butyl-calix[4,6,8]arene-SGCn (SGC4, SGC6, SGC8) are prepared. The products are characterized by FTIR, elemental analysis, thermal gravimetric analysis and scanning electron microscope. Static adsorption behavior is studied by using SGC8 as adsorbent, butyl Rhodamine B (BRB) solution as simulation dye wastewater. The adsorption of BRB onto SGC8 fits the se...

To improve the coal permeability and outburst prevention, coal seam water injection and a series of outburst prevention measures were tested in outburst coal mines. These methods have become important technologies used for coal and gas outburst prevention and control by increasing the external moisture of coal or decreasing the stress of coal seam and changing the coal pore structure and gas de...

Two SiO2 and three Al2O3 adsorbents with varying degrees of mesoporosity (pore diameter 2-50 nm) were reacted with 2,4-dichlorophenoxyacetic acid (2,4-D) at pH 6 to investigate the effects of intraparticle mesopores on adsorption/desorption. Anionic 2,4-D did not adsorb onto either SiO2 solid, presumably because of electrostatic repulsion, but it did adsorb onto positively charged Al2O3 adsorbe...

The dissociative adsorption of H2 on the Si(001) surface is theoretically investigated for several reaction pathways using quantum Monte Carlo methods. Our reaction energies and barriers are at large variance with those obtained with commonly used approximate exchange-correlation density functionals. Our results for adsorption support recent experimental findings, while, for desorption, the cal...

Reactive Red 120 was utilized as an affinity dye-ligand to modify the surface of magnetic chitosan microspheres to improve the adsorption capacity for lysozyme. The impact of pH, ionic strength, adsorption time and initial lysozyme concentration on the adsorption of lysozyme from aqueous solutions was investigated. An increased adsorption amount of 116.9 mg/g lysozyme on Reactive Red 120 modifi...

The interaction of acetone with single wall carbon nanotubes (SWCNTs) was studied by temperature programmed desorption with mass spectrometry (TPD-MS), after reflux, sonication, or exposure to 7.6 Torr of acetone vapors at room temperature. Acetone molecules adsorb strongly on SWCNTs desorbing at 400–900 K, corresponding to desorption energies of 100–225 kJ/mol, as intact molecules. Exchange of...

The fate of Pb in the environment is highly dependent on sorption and desorption reactions on solid surfaces. In this study Pb sorption and desorption kinetics on γ-Al2O3 at pH 6.50, I ) 0.1 M, and [Pb]initial ) 2 mM were investigated using both macroscopic and spectroscopic measurements. X-ray absorption fine structure (XAFS) spectroscopy revealed a Pb-Al bond distance of 3.40 Å, consistent wi...