Humic acids and clays are important soil components that influence the sorption and desorption of organic contaminants; however, it is unclear how humic acids influence the sorption of organic contaminants onto clays and their subsequent desorption. Sorption and desorption of 2,4,6-trichlorophenol (2,4,6-TCP) by and from humic acid-modified K(+)- and Ca(2+)-montmorillonite and -illite were comp...

Lignin, a natural renewable material, was incorporated in a series of polydimethylsiloxane/silica composites. Besides the effect as bulk filler, the presence of lignin determines the change of some properties among them being surface properties that were evaluated by contact angle and water sorption measurements. The contact angles were determined in static regime by using the sessile drop tech...

The sorption of lead ion onto palm kernel fiber was studied by performing batch kinetic sorption experiments. The batch sorption model, based on a pseudo-second-order mechanism, was applied to predict the rate constant of sorption, the equilibrium capacity and the initial sorption rate with the effects of the initial solution pH and fiber dose. Equilibrium concentrations were evaluated with the...

Strontium sorption to amorphous silica and goethite was measured as a function of pH and dissolved strontium and carbonate concentrations at 25 degrees C. Strontium sorption gradually increases from 0 to 100% from pH 6 to 10 for both phases and requires multiple outer-sphere surface complexes to fit the data. All data are modeled using the triple layer model and the site-occupancy standard stat...

An improved version of the manometric apparatus and its procedures for measuring excess sorption of supercritical carbon dioxide are presented in detail with a comprehensive error analysis. An improved manometric apparatus is necessary for accurate excess sorption measurements with supercritical carbon dioxide due to the difficulties associated with the high sensitivity of density for pressure ...

Poly urea-formaldehyde was synthesized simply and rapidly from urea and formaldehyde by condensation polymerization and studied for the sorption of trace acid blue from aqueous solution. The optimum pH value for sorption of the acid blue was 4. Experimental results showed that the sorption capacity of poly urea-formaldehyde for acid blue was determined. The synthetic polymer can be reused for 5...

Chitosan functionalized with 2-mercaptobenzimidazole (2-MBI) (i.e. [email protected]) shows high sorption capacity (i.e., 1.28 mmol MB g−1) for methylene blue (MB) (at pH close to 9.3). Sorption is weakly decreased (by less than 25%) by NaCl concentration (up 45 g L−1). The (slightly endothermic) fitted the Langmuir equation. kinetic profile pseudo-first order rate equation (PFORE): equilibrium...

Sorption of biologically active substances by ion exchangers, characteristic features of such substances and their low stability levels are discussed. Main principles of choosing ion exchangers for isolation and purification of organic substances are developed. Investigation of ion exchange with respect to organic substances revealed specific relationships in their sorption and indicated a nece...

14 The mechanisms of sorption of four steroidal hormones – estradiol, estrone, progesterone and 15 testosterone – to electrodialysis (ED) membranes were investigated as a function of solution pH 16 and presence of humic acid (HA). Hormone-membrane partition coefficients (log KAEM/CEM) 17 determined through sorption isotherm experiments suggested that hormone sorption was due to 18 hydrogen bond...

This study compares the abilities of four low-cost materials: peels of peas, broad bean, and medlar, respectively and fig leaves, to remove cadmium from aqueous solutions. Kinetic data and equilibrium sorption isotherms were measured in batch conditions. Kinetics of cadmium sorption was contact time, initial cadmium concentration and sorbent type dependent. The results also showed that the kine...