Sulfate desorption and mobility in soil can be of both environmental and agronomic importance. This study was conducted to describe the desorption of SO 4 from agricultural soils under experimental conditions applicable to the movement of SO 4 in overland flow and runoff waters. The kinetics of SO 4 desorption from soil were investigated at five different water/soil ratios (10:1-400:1), five ti...

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...

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...

We investigated the sorption kinetics of pentachlorophenol (PCP) on soil at a pH of 4.1 using batch techniques. A multiple spiking methodology was employed to circumvent the solubility limitation of PCP. The ratio of sorbed PCP to solution-phase PCP (S/C) after 2-4 days of equilibration was concentration dependent. It decreased from 90 to 60 L/kg with a 4-fold increase in the total PCP concentr...

The dynamics of oligomer desorption from surfaces have been studied by measuring the desorption kinetics of a set of n-alkanes from the surface of single crystalline graphite. Desorption rates were measured using a set of 21 monodispersed n-alkanes (CNH2N12,5<N<60) each adsorbed at coverages in the range ,0.1 to .1 monolayers. Desorption is observed to be a first-order process with a desorption...

We present Temperature Programmed Desorption (TPD) experiments of CO and N 2 ices in pure, layered and mixed morphologies at various ice " thicknesses " and abundance ratios as well as simultaneously taken Reflection Absorptio and to derive the kinetics for desorption, mixing and segregation. Forn Infrared Spectra (RAIRS) of CO. A kinetic model has been developed to constrain the binding energi...

H.-R. Schulten and W. D. Lehmann Institute of Physical Chemistry, University of Bonn, Wegeierstraße 12, D-5300 Bonn Z. Naturforsch. 83 b, 770-781 (1978); received March 21, 1978 Field Desorption Mass Spectrometry, a-Amino Acid Methionine The fragmentation of methionine in field desorption mass spectrometry has been studied. Decomposition mechanisms are described which are based on stable isotop...

The dynamics of oligomer desorption from surfaces has been studied by measuring the desorption kinetics of a set of straight chain alkanes [ H(CH2)(n)H, with n = 5 to 60] from the surface of single crystalline graphite. Desorption is observed to be a first-order process and the preexponent of the desorption rate constant has a value nu = 10(19.6+/-0.5) sec(-1) and is independent of the oligomer...