in this study, the batch equilibrium method was used to conduct metribuzin adsorption/desorption experiments with eight soils from different regions of iran. the results indicated that the organic carbon (oc) content, clay content, cation exchange capacity (cec), and ph had a combined effect on the metribuzin adsorption on soil. under the experimental conditions, the adsorption amount of metrib...

moisture sorption isotherms for pistachio powder were determined by gravimetric method according to cost 90 project at temperatures of 15, 25, 35, and 40oc . maximum hysteresis level in sorption isotherms curve was observed at the range of water activity 0.2-0.7 . on the other hand hysteresis was diminished between adsorption-desorption isotherm curves when temperature reached 40oc. some mathem...

abstract herbicides are the main sources of soil and water pollution in paddy fields. herbicides mobility to the surface and ground water is a major concern for human health and the environment. it is, therefore, necessary to investigate their fate and their interactions in natural ecosystems. to meet this purpose, field experiments were conducted to measure kinetic of thiobencarb dissipation i...

the potential of six economically cheap agricultural waste materials, viz. rice husk, betel nutpeels, sugarcane molasses, tea waste, mustard oil cake and saw dust, was investigated for copper and leadremoval from aqueous solutions under batch and continuous conditions. the effect of ph, contact time,sorbent dose and initial metal ion concentration on the uptake of copper and lead was first exam...

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...

The dissociative adsorption energy of oxygen on Pt(111) is known to be coverage dependent. Simple Redhead analysis of temperature programmed desorption (TPD) experiments that assumes a coverage independent desorption barrier can lead to errors in estimated properties such as desorption barriers and adsorption energies. A simple correction is to assume a linear coverage dependence of the desorpt...

We report a systematic experimental investigation of the mechanism of desorption of chlorobenzene molecules from the Si(111)-(7 x 7) surface induced by the STM at room temperature. We measure the desorption probability as a function of both tunneling current and a wide range of sample bias voltages between -3 V and +4 V. The results exclude field desorption, thermally induced desorption, and me...

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...

Temperature programmed desorption TPD has been used to investigate the behavior of cyclohexane C6H12 on Zr 0001 and the effects of 500 eV electron bombardment on its desorption characteristics. Following adsorption at 150 K, molecular desorption above 600 K suggests exceptionally strong interaction between C6H12 and Zr 0001 . These high-temperature desorption features shift to higher temperatur...