Soil phosphorus (P) solubility and kinetics partly control dissolved P losses to surface water uptake by plants. While previous studies have focused on batch techniques for measuring soil desorption kinetics, flow-through are more realistic because they simulate removal from the system, akin runoff, leaching, plant uptake. The objectives were measure a technique at two flow rates several method...

Adsorption-desorption of arsenic is the primary factor that impacts the bioavailability and mobility of arsenic in soils. To examine the characteristics of arsenate [As(V)] adsorption-desorption, kinetic batch experiments were carried out on three soils having different properties, followed by arsenic release using successive dilutions. Adsorption of As(V) was highly nonlinear, with a Freundlic...

S. A. FitzGerald,1 R. Hannachi,1 D. Sethna,1 M. Rinkoski,1 K. K. Sieber,2 and David S. Sholl2,3 1Oberlin College, Department of Physics, Oberlin, Ohio 44074, USA 2Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA 3National Energy Technology Laboratory, Pittsburgh, Pennsylvania 15236, USA sReceived 27 July 2004; revised manuscript received 30 Sep...

in the present investigation, dead bacterium biomass streptomyces rimosus was used as an inexpensive and efficient biosorbent for cr (iii) removal from aqueous solution. the bacterial biomass was treated with 0.1 m naoh. sorption level of 65 mg/g was observed at ph 4.8 while precipitation effect augmented this value at higher ph range. chromium desorption increased with decreasing desorption ag...

Reflection absorption infrared spectroscopy (RAIRS) and temperature programed desorption (TPD) have been used to probe the adsorption and desorption of ethanol on highly ordered pyrolytic graphite (HOPG) at 98 K. RAIR spectra for ethanol show that it forms physisorbed multilayers on the surface at 98 K. Annealing multilayer ethanol ices (exposures >50 L) beyond 120 K gives rise to a change in m...

Carbon nanotubes have been proposed as promising hydrogen storage materials for the automotive industry. By theoretical analyses and total-energy density functional theory calculations, we show that contribution from physisorption in nanotubes, though significant at liquid nitrogen temperature, should be negligible at room temperature; contribution from chemisorption has a theoretical upper lim...

The kinetics of thermal desorption from an excimer-laser-melted surface, on which diffusion into the bulk competes with desorption, is numerically evaluated and compared with a variety of experimental data for the case of Cl on Si: Auger electron spectroscopy, time-of-flight mass spectrometry, secondary-ion-mass spectrometry, and transient reflectivity. The model calculations involve nonequilib...

The kinetics of isothermal desorption of hydrogen from InNð000 1Þ have been investigated using surface vibrational spectroscopy. Reductions in intensity of the N–H stretching and bending vibrations in high resolution electron energy loss spectra (HREELS) upon annealing indicated loss of surface hydrogen and was attributed to recombinative desorption. Hydrogen completely desorbs from the InN sur...

The enantiospecific desorption kinetics of R- and S-propylene oxide (PO) from a Cu(100) surface modified by enantiomerically pure D- or L-lysine have been studied using temperature programmed desorption. These experiments have used R- or S-PO as the chiral probe for study of enantiospecific adsorption on Cu(100) surfaces modified with D- or L-lysine. This chiral probe/modifier/Cu system manifes...

The problem of equilibrium and kinetics for adsorption] desorption of condensable ®apors in porous media is studied experimentally and theoretically. For adsorption, the ( network model for diffusion based on pore blocking theory with percolation in the ) network added by effecti®e medium approximation is further impro®ed. A new predicti®e model based on properties of the Bethe lattices is prop...