The contribution of variable grain sizes to uranium adsorption/desorption was studied using a sediment from the US DOE Hanford site. The sediment was wet sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.053-0.2 mm), and clay/silt fraction (<0.053 mm). For each size fraction and their composite (sediment), batch and flow-cell experiments were performed ...

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 effective management of sewage sludge materials in an environmentally and economically acceptable way is through the pyrolytic conversion of the sludge to biochar and its use for agricultural purposes. The aims of this work were: (1) to assess the effect of biochar prepared from sewage sludge at two different temperatures (350 ºC and 650 ºC) on the adsorption/desorptio...

plants uptake boron (b) from the soil solution, in which boron concentration is controlled by adsorption and desorption reactions on soil organic and inorganic colloids. considering the importance of aluminosilicate minerals in ion adsorption and desorption reactions in soil, in this research, b adsorption behavior on kaolinite was studied as a function of equilibrium concentration, ph, kaolini...

the adsorption and desorption properties of sqd-85 resin for cu(ii) had been investigated. a series of experiments were conducted in a batch system to assess the effect of the system variables, i.e. initial ph, contact time and temperature. the results show that the optimal ph for the adsorption was 5.99 in the hac-naac system, and the maximum adsorption capacity was estimated to 324 mg/g at 29...

Today, sulfur removal from fuels has improved by new adsorbents such as zeolites that needs extensive studies. This study investigates the feasibility of sulfur compounds adsorption on improved nano zeolite existing in organic fuels and desorption of them from nano-adsorbent.Some properties of improved nano zeolite were analyzed to receive better sulfur compounds adsorption.<e...

this study was carried out to obtain quantitative relationships between zn in equilibrium solution and that retained by 20 calcareous soils. soils were brought into equilibrium with varying solution concentrations of zn, and the amounts removed from solution were used to check the fit to six adsorption isotherms, namely, freundlich, langmuir, temkin, gunary, two surface langmuir and adjusted fr...

The garden grass (GG) was firstly used to remove copper(II) from water as bioadsorbent. From the results of characterisation, the GG had the merits of high specific surface area, significant adsorption sites and functional groups. Copper-adsorption significantly depends on the initial copper concentrations, contact time, pH, adsorbent doses, particle sizes and temperature. The positive values o...

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...

adsorption of anilofos was studied in four soils (topsoil from alfisol, inceptisol, oxisol and vertisol). the order of adsorption of anilofos was vertisol > oxisol > alfisol > inceptisol. the soil sorption coefficient k and the soil organic carbon sorption coefficient koc are the basic parameters used for describing the environmental fate of the herbicides. in top soil the calculated k values ...