A method using heated and superheated (subcritical) water is described for rapid prediction of long-term desorption rates from contaminated geosorbents. Rates of contaminant release are measured at temperatures between 75 and 150 degrees C using a dynamic water desorption technique. The subcritical desorption rate data are then modeled to calculate apparent activation energies, and these activa...

Tetraethylenepentamine (TEPA)-based mesoporous MCM-41 is used as the adsorbent to determine the CO2 desorption kinetics of amine-modified materials after adsorption. The experimental data of CO2 desorption as a function of time are derived by zero-length column at different temperatures (35, 50, and 70 ◦C) and analyzed by Avrami’s fractional-order kinetic model. A new method is used to distingu...

abstract the availability of heavy metals in the soil is related to their partitioning between solution and solid phases and expressed by sorption isotherm. twenty surface soil samples (0-30 cm) belonging to five soil subgroups were taken from agricultural regions of western azerbaijan province. the sorption isotherms of pb were determined by equlibrating the soil with solutions containing 0, 1...

in this study, the adsorption of hexavalent chromium and zinc ions from the solution is investigated by raw red mud and mechanical-chemical activated red mud along with the possibility of selective reclamation of these ions from the solution. the mechanical-chemical activation of red mud was done by employing high-energy milling and subsequent acid treatment with hno3. raw red mud (rrm) and mec...

polypyrrole (ppy/cl) and polyaniline (pani/cl) synthesized chemically onto sawdust (sd)was used for removal of thiocyanate (scn-) ions from aqueous solutions. the effect of someimportant parameters such as ph, initial concentration, sorbent dosage, and contact time onuptake of scn- was investigated. ppy/sd was found to be much more effective sorbent thanpani/sd for uptake scn- from aqueous solu...

This investigation was undertaken to determine whether desorption hysteresis effects were dependent upon methods used in obtaining desorption data. Adsorption-desorption isotherms were obtained for two organophosphorus insecticides in aqueous suspensions of a clay, a sandy loam, and an organic soil. Desorption isotherms were obtained using both the consecutive desorption method and the dilution...

The desorption characteristics of lead in two variable charge soils (one developed from Arenaceous rock (RAR) and the other derived from Quaternary red earths (REQ)) were studied, and the effects of pH value, organic acid, and competitive ions were examined. Desorption of Pb(2+) decreased from nearly 100.0 to 20.0% within pH 1.0-4.0 in both soils, and then the decrease diminished at pH > 4.0. O...

Hexagonal boron nitride (h-BN) is known as an effective additive to improve the hydrogen de/absorption properties of hydrogen storage materials consisting of light elements. Herein, we report the unique hydrogen desorption properties of LiAlH4/h-BN composites, which were prepared by ball-milling. The desorption profiles of the composite indicated the decrease of melting temperature of LiAlH4, t...

land treatment method of municipal and industrial wastewaters for utilization of nutrients in the wastes for raising useful crops and tertiary(or advanced) treatment of the water for improving stream quality or to recharge falling water tables is increasing in some parts of the world, particulary in the arid area. as emphasis in this type of treatment method and prevention of surface and underg...

Measures of desorption are currently considered important as potential surrogates for bioaccumulation as measures of the bioavailability of sediment-sorbed contaminants. This study determined desorption rates of four laboratory spiked compounds, benzo[a]pyrene (BaP), 2,4,5,2',4',5'-hexachlorobiphenyl (HCBP), 3,4,3',4'-tetrachlorobiphenyl (TCBP), and pyrene (PY), to evaluate the effect of sedime...