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Adsorption Efficiency (adsorption + efficiency)

Distribution by Scientific Domains

Chemistry	80%

Selected Abstracts

Adsorption properties of microwave synthesized inorgano,organo montmorillonite

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2010
Miray Emreol
Abstract The aim of this study is to determine the adsorption properties of microwave synthesized inorgano,organo montmorillonites. Microwave irradiation is preferred because of its low time and energy consumption properties, forming an advantage in industrial applications. In addition to the intercalation of Keggin and hexadecyltrimethylammonium (HDTMA+) cations, the aging process of pillaring solution was also carried out through the microwave irradiation. Both inorgano clays, namely the parents, and their inorgano,organo derivatives, were prepared by using the same amounts of aluminum by keeping the OH,/Al3+ and Al3+/clay ratios constant. The HDTMA+/clay ratio was changed in inorgano-organo clays (IOCs) during the preparation. The effects of these parameters on the surface properties and adsorption behaviors of the samples were investigated by conducting X-ray diffraction (XRD), Fourier transform infrared (FTIR) and simultaneous thermal analyses (STA), as well as batch adsorption experiments, in which phenol was used as a model pollutant. The results of XRD analyses reveal that the intercalation is successfully achieved. The existence of the Keggin and HDTMA+ cations was observed in FTIR spectra of the samples. Through the STA, it was determined that the existence of organic layer increases the dehydroxylation temperature and the thermal behavior of inorgano-organo montmorillonites strongly depends on the structure of the parent clay. An increase in the adsorption efficiencies with increasing HDTMA+/clay ratio was observed, except with the highest ratio. The behavior of this sample was explained by the formation of the second HDTMA+ layer leading to the hydrophilic surface formation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Adsorption of heavy metals from aqueous solutions with by-products of the steelmaking industry

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2005
M Isabel Martín
Abstract This paper describes the use of two steelmaking industry by-products (rolling mill scale and blast furnace sludge) as adsorbents for removing heavy metals from aqueous effluent solutions. The adsorption of Pb2+, Zn2+ and Cd2+ on these materials has been studied by the determination of adsorption isotherms from solutions of controlled ionic strength. The effect of time, equilibrium temperature and metal solution concentration on adsorption efficiency was evaluated. The adsorption processes are analysed using the Langmuir theory. Desorption and dumping processes for the metals from loaded steelmaking industry by-products were also studied under different experimental conditions. The by-products were shown to be effective adsorbents for the studied cations in aqueous solutions within the range of working concentrations. Copyright © 2005 Society of Chemical Industry [source]

Dye-affinity hollow-fibres and their lysozyme adsorption,desorption characteristics

POLYMER INTERNATIONAL, Issue 10 2001
Serap, enel
Abstract Dye-affinity adsorption is increasingly used for protein separation. Hollow-fibres have advantages as adsorbents in comparison to conventional bead supports because they are not compressible and can eliminate internal diffusion limitations. The aim of this study was to explore in detail the performance of polyamide hollow-fibres to which Reactive Green HE-4BD was attached for adsorption of lysozyme. The hollow-fibre was characterized by scanning electron microscopy. These dye-carrying hollow-fibres (26.3,µmol,g,1) were used in the lysozyme adsorption,elution studies. The effect of initial concentration of lysozyme and medium pH on the adsorption efficiency of dye-attached hollow-fibres was studied in a batch system. The non-specific adsorption of lysozyme on the polyamide hollow-fibres was 1.8,mg,g,1. Reactive Green HE-4BD attachment significantly increased the lysozyme adsorption up to 41.1,mg,g,1. Langmuir adsorption model was found to be applicable in interpreting lead adsorption by Reactive Green HE-4BD attached hollow fibres. Significant amount of the adsorbed lysozyme (up to 95%) was eluted in 1,h in the elution medium containing 1.0,M NaSCN at pH 8.0. In order to determine the effects of adsorption conditions on possible conformational changes of lysozyme structure, fluorescence spectrophotometry was employed. We concluded that polyamide dye-affinity hollow-fibres can be applied for lysozyme adsorption without causing any significant conformational changes. Repeated adsorption,elution processes showed that these dye-attached hollow-fibres are suitable for lysozyme adsorption. © 2001 Society of Chemical Industry [source]

Influence of Cationic Starch Adsorption on Fiber Flocculation

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 8 2009
N. Zakraj
Abstract The adsorption of cationic starch on hardwood fibers and its influence on flocculation were studied in relation to the dosage of cationic starch, the effect of shear forces and the presence of different concentrations of inorganic salts in the paper stock. Flocculation was monitored by means of a focused beam reflectance measurement (FBRM) probe. It was established that floc size at low shear rates depends on adsorption efficiency. At high shear forces, flocs were irreversibly decomposed despite the presence of a higher amount of adsorbed cationic starch on the fibers. Therefore, flocculation was produced by a bridging mechanism. The results show a significant effect of inorganic salts on the adsorption of cationic starch on fibers. Low concentrations of inorganic salts usually improved the adsorption process while higher concentrations (> 0.01 mol/L) reduced the adsorption and limited the flocculation process. [source]

Photochemical Key Steps in the Synthesis of Surfactants from Furfural-Derived Intermediates

CHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 12 2009
Abdoulaye Gassama Dr.
Abstract Furfural is oxidized to 2[5H]-furanone by using hydrogen peroxide or to 5-hydroxy-2[5H]-furanone by using photo-oxygenation. An amine function is introduced by photochemically induced radical addition of tertiairy amines, some of which carry an n -alkyl side chain as hydrophobic moiety. These amines are produced from fatty aldehydes and cyclic secondary amines. The resulting adducts are transformed into amphoteric surfactants possessing an ammonium and a carboxylate function. Amphoteric (pKN and isoelectric point) and surfactant properties such as the critical micelle concentration and the adsorption efficiency are determined. [source]