The Experts below are selected from a list of 587649 Experts worldwide ranked by ideXlab platform
Jun Zhou - One of the best experts on this subject based on the ideXlab platform.
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kinetic studies of adsorption of pb ii cr iii and cu ii from aqueous solution by sawdust and modified peanut husk
Journal of Hazardous Materials, 2007Co-Authors: Jianping Zhai, Wenyi Zhang, Mingmei Wang, Jun ZhouAbstract:Sawdust and modified peanut husk were used as adsorbents to remove Pb(II), Cr(III) and Cu(II) from aqueous solution. Results of kinetic experiments demonstrated that the adsorption was effective and rapid. Three different kinds of kinetic models (i.e., intraparticular diffusion model, Lagergren-first-order and Second-Order Equations) were used to investigate the adsorption mechanisms. The adsorption of heavy metals on sawdust and modified peanut husk is not an intraparticular diffusion control. The kinetic adsorption data can be described by the Second-Order Equation and the adsorption might be a rate-limiting control. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherms, which gave good fits with both isotherms.
Gordon Mckay - One of the best experts on this subject based on the ideXlab platform.
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Elovich Equation and modified Second-Order Equation for sorption of cadmium ions onto bone char
Journal of Chemical Technology and Biotechnology, 2000Co-Authors: Chun Wai Cheung, John F Porter, Gordon MckayAbstract:The removal of cadmium ions from water by sortion onto bone char has been studied. Bone char, traditionally used for colour removal in sugar refining, is produced by the carbonisation of animal bone. Batch experiments were carried out to study the effects of initial cadmium ion concentration and bone char mass on the sorption rate. The experimental contact data were analysed using the Elovich model, previously used to describe the kinetics of gas adsorption on solids, and the Ritchie model, a modified Second-Order kinetics Equation. Initial analysis of the data, using the Ritchie model, was poor and therefore a modification was incorporated to make the Ritchie model predictions correlate the experimental data more accurately. Both the Elovich and modified Ritchie Equations accurately predict the sorption capacity of cadmium on bone char, however, the sorption kinetics, derived from the differential forms of the two Equations, were correlated better using the Elovich Equation. (C) 2000 Society of Chemical Industry.
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a comparison of chemisorption kinetic models applied to pollutant removal on various sorbents
Process Safety and Environmental Protection, 1998Co-Authors: Yuhshan Ho, Gordon MckayAbstract:A comparison of kinetic models describing the sorption of pollutants has been reviewed. The rate models evaluated include the Elovich Equation, the pseudo-first order Equation and the pseudo-second order Equation. Results show that chemisorption processes could be rate limiting in the sorption step. The pseudo-second order Equation may be applied for chemisorption processes with a high degree of correlation in several literature cases where a pseudo-first order rate mechanism has been arbitrarily assumed.
J. B. Mcleod - One of the best experts on this subject based on the ideXlab platform.
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On the periodic solutions of a forced Second-Order Equation
Journal of Nonlinear Science, 1991Co-Authors: S. P. Hastings, J. B. McleodAbstract:We study the Equations for two-dimensional irrotational motion induced in a rectangular tank of water which is forced to oscillate horizontally in a periodic fashion (“shallow water sloshing”). The problem reduces to a Second-Order non-autonomous ordinary differential Equation. We rigorously show the existence of many solutions obtained previously by numerical computations, and in addition we show that there are many other bounded solutions. We use simple shooting to obtain irregular solutions of the kind obtained by the methods of dynamical systems. In addition, we obtain a kind of “kneading” theory whereby we can order the initial conditions according to the pattern of “spikes” exhibited by the solutions.
Kostas A. Matis - One of the best experts on this subject based on the ideXlab platform.
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adsorptive removal of arsenites by a nanocrystalline hybrid surfactant akaganeite sorbent
Journal of Colloid and Interface Science, 2006Co-Authors: Eleni A. Deliyanni, L Nalbandian, Kostas A. MatisAbstract:Removal of toxic arsenite ions from aqueous solutions was investigated using an innovative hybrid nanocrystalline surfactant-modified akaganeite. This sorbent was prepared using ferric chloride as the precursor and a cationic surfactant, hexadecyltrimethylammonium bromide. From the experimental work, the material was found to be an effective adsorbent for the separation of arsenites. The chemical kinetics of the process was studied, described by a pseudo-Second-Order Equation. The Freundlich adsorption isotherm was determined to examine the mechanism of sorption. FTIR measurements and XPS analysis gave useful information both on the sorbent synthesized and on the arsenite removal process.
Yuanyuan Wang - One of the best experts on this subject based on the ideXlab platform.
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An efficient complex‐frequency shifted‐perfectly matched layer for second‐order acoustic wave Equation
International Journal for Numerical Methods in Engineering, 2013Co-Authors: Youneng Ma, Jinhua Yu, Yuanyuan WangAbstract:SUMMARY In the context of simulations of wave propagations in unbounded domain, absorbing boundary conditions are often used to truncate the simulation domain to a finite space. Perfectly matched layer (PML) has proven to be an excellent absorbing boundary conditions. However, as this technique was primarily designed for the first-order Equation system, it cannot be applied to the Second-Order Equation system directly. In this paper, based on a complex-coordinate stretching technique, we developed a novel, efficient auxiliary-differential Equation form of the complex-frequency shifted-PML for the Second-Order Equation system. This facilitates the use of complex-frequency shifted-PML in acoustic simulations based upon wave Equations of Second-Order form. Compared with previous state-of-the-art methods, the proposed one has the advantage of simpler implementation. It is an unsplit-field scheme that can be extended to higher-order discretization schemes conveniently. Numerical results from both homogeneous and heterogeneous computational domains are provided to illustrate the validity of the method. Copyright © 2013 John Wiley & Sons, Ltd.