The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Wan Chuanhong - One of the best experts on this subject based on the ideXlab platform.
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study on adsorption property of the biomodified rice straw on azure a in simulated wastewater
Journal of Anhui Agricultural Sciences, 2013Co-Authors: Wan ChuanhongAbstract:[Objective] The research aimed to study adsorption property of the biomodified rice straw on azure A in simulated wastewater.[Method]By microbial metabolism,rice straw was conducted bio-modification.Adsorption property of the rice straw on azure A in simulated wastewater before and after modification was studied.[Result]When azure A in simulated wastewater was 100 mg/L,the optimum dosage of adsorbent was 10 g/L,and the optimal pH was 1-2.Two kinds of adsorbents both reached adsorption equilibrium at 35 min,and adsorption corresponded with pseudo-second kinetic Equation.Adsorption isotherms of the biomodified rice straw and natural rice straw both highly corresponded with Freundlich Equation and Langmuir Equation.The maximum adsorption amounts of biomodified rice straw and natural rice straw were respectively 15.80 and 13.17 mg / g.[Conclusion] Modification of the rice straw by microorganism could improve adsorption amount of the dye in simulated wastewater,which was economic,environmental,simple and efficient,and had higher research value and application prospect.
Janet A W Elliott - One of the best experts on this subject based on the ideXlab platform.
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role of precipitating solute curvature on microdrops and nanodrops during concentrating processes the nonideal ostwald Freundlich Equation
Journal of Physical Chemistry B, 2014Co-Authors: Fatemeh Eslami, Janet A W ElliottAbstract:The microdrop concentrating process, which is one of the manipulations in the microdrop platform of microfluidic technologies, is a useful technique, especially in biological applications. This process may encounter a solute precipitation within the droplet if the solute reaches its solubility limit. In the case of very small solid precipitates, the solid particle size will affect the solubility limit, and the Ostwald–Freundlich Equation (OFE) describes this dependency. Including the OFE in analysis affects the design parameters for this type of system and the system’s thermodynamic stability. Here, by means of Gibbsian surface thermodynamics, we provide the thermodynamic description and stability analysis of this system considering the role of the Ostwald–Freundlich Equation. Previously we have investigated the stability of the system without considering the OFE, which is equivalent to using a constant solubility limit. Herein it is shown that the OFE significantly affects the results for nanometer drop ...
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role of precipitating solute curvature on microdrops and nanodrops during concentrating processes the nonideal ostwald Freundlich Equation b
The Journal of Physical Chemistry, 2014Co-Authors: Fatemeh Eslami, Janet A W ElliottAbstract:The microdrop concentrating process, which is one of the manipulations in the microdrop platform of microfluidic technologies, is a useful technique, especially in biological applications. This process may encounter a solute precipitation within the droplet if the solute reaches its solubility limit. In the case of very small solid precipitates, the solid particle size will affect the solubility limit, and the Ostwald–Freundlich Equation (OFE) describes this dependency. Including the OFE in analysis affects the design parameters for this type of system and the system’s thermodynamic stability. Here, by means of Gibbsian surface thermodynamics, we provide the thermodynamic description and stability analysis of this system considering the role of the Ostwald–Freundlich Equation. Previously we have investigated the stability of the system without considering the OFE, which is equivalent to using a constant solubility limit. Herein it is shown that the OFE significantly affects the results for nanometer drop sizes and that various stability behaviors are possible.
Baoshan Xing - One of the best experts on this subject based on the ideXlab platform.
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phenanthrene sorption to soil humic acid and different humin fractions
Environmental Science & Technology, 2007Co-Authors: Bei Wen, Shahamat U. Khan, Jingjing Zhang, Shuzhen Zhang, Xiaoquan Shan, Baoshan XingAbstract:This study was undertaken to provide an insight into the effect of heterogeneous soil organic matter (SOM) on the sorption of phenanthrene. Humic acid (HA) and humin were extracted from a peat soil. Humin was further fractionated into bound-humic acid (BHA), lipid, and insoluble residue (IR) fractions. Heterogeneous natures of these fractions were characterized by elemental analysis, ultraviolet−visible spectroscopy, Fourier transform infrared spectroscopy, and solid-state 13C NMR. Aliphaticity of the fractions followed the order lipid >BHA > HA > IR, while the polarity order was IR > BHA> HA > lipid. Sorption of phenanthrene on these fractions fitted the Freundlich Equation, suggesting that phenanthrene sorption isotherms of lipid were almost linear (N = 0.993), while those of HA, BHA, and IR were nonlinear, with N values ranging from 0.723 to 0.910. The N values followed the order lipid > HA > BHA > IR and were significantly correlated inversely with their polarities (p < 0.05). Organic carbon-normalize...
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distribution of sorbed phenanthrene and pyrene in different humic fractions of soils and importance of humin
Environmental Pollution, 2006Co-Authors: Bo Pan, Baoshan Xing, W X Liu, Shu Tao, Xiumei Lin, Xianming Zhang, Yanxu Zhang, Yang Xiao, Hancheng Dai, Huishi YuanAbstract:Contributions of fulvic-humic acids (FA/HA) and humin (HM) to sorption of phenanthrene (PHE) and pyrene (PYR) in a soil were differentiated using a humic separation procedure after multi-concentration sorption experiments. It was found that the amount of solutes in FA/HA did not change significantly after 48 h, while that in HM increased continuously and slowly up to the end of the experimental period (720 h), indicating that HM was the main region for slow sorption. Based on the fitting results using Freundlich Equation, it was found that nonlinearity of both solutes was greater in HM than in FA/HA, consistent with the sorption characteristics of individually extracted HA and HM in a separate experiment. The observed nonlinearity of the solute distribution was confirmed by using three other soil samples with organic carbon contents ranging from 0.7 to 7.9%. Distribution dynamics of PHE and PYR among various fractions were also discussed.
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sorption of pahs by aspen wood fibers as affected by chemical alterations
Environmental Science & Technology, 2006Co-Authors: Liyuan Huang, Thomas B Boving, Baoshan XingAbstract:Sorption and desorption experiments for phenanthrene and pyrene, using untreated (UTR) and treated (bleaching and hydrolysis) aspen wood fibers, were examined to understand their sorption mechanisms. The wood was characterized by elemental and porosity analysis, solid-state 13C NMR, and diffuse reflectance infrared Fourier transform spectroscopy. Bleaching removed aromatic components, yielding the highest polarity and increased porosity, whereas hydrolysis removed a large percentage of hemicellulose and parts of amorphous cellulose, producing a matrix with more aromatic moieties, lower polarity, and higher porosity than that of the UTR wood fibers. All isotherms fitted well to the Freundlich Equation and the N values had a decreasing trend from bleached (BL), UTR, low-temperature hydrolyzed to high-temperature hydrolyzed (HHY) wood fibers. BL fibers had the lowest sorption capacity (KOC) for both phenanthrene and pyrene. HHY had the highest KOC because of its high aromatic carbon content and low polarity....
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a unified sorption variable for environmental applications of the Freundlich Equation
Journal of Environmental Quality, 1999Co-Authors: Z Chen, Baoshan Xing, W B McgillAbstract:The Freundlich Equation (x/m = K f C 1/n e ) has been used widely in sorption studies in chemistry and environmental research. Two problems arise in comparing sorbate-sorbent systems if C e ¬= 1 or if 1/n values differ. First, it is often not possible to compare K f values from the literature if they were derived from different units of x/m and C e . Second, the exponent 1/n, determines the interpretation of K f . Consequently, comparing values of K f or K oc-f is problematic. We propose a way to characterize sorption dynamics in systems that follow the Freundlich isotherm that avoids problems caused by comparing K f values. We show that: (i) The units of K f are: mmol 1-1/n kg -1 L 1/n , or mg 1-1/n kg -1 L 1/n , etc. depending on the units of x/m and C e . Therefore, K f parameters cannot be compared among samples whenever the 1/n parameters are different; (ii) For K f values that are associated with different units, the units-conversion factor for K f is also a function of 1/n. It has the form of: A 1-1/n , where A is the units-conversion factor if 1/n = 1; (iii) We propose a new variable, K u , to unify the units of K f and to conduct sensitivity analyses of K f and 1/n. Numerically K u is the slope, (x/m)/C e , of the sorption isotherm at any value of C e or x/m and has units of L kg -1 .
Maria De La Luz Mora - One of the best experts on this subject based on the ideXlab platform.
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modifications to the Freundlich Equation to describe anion sorption over a large range and to describe competition between pairs of ions
European Journal of Soil Science, 2005Co-Authors: N J Barrow, Paula Cartes, Maria De La Luz MoraAbstract:Summary We measured sorption of selenite and phosphate, both separately and in competition, in a Chilean Andisol. We also used previously published data for competitive sorption of arsenate and phosphate by a clay subsoil. We wrote computer programs that allowed us to compare the fits of differing versions of Equations to describe individual sorption and competitive sorption. For the selenite–phosphate data, the index term of the Freundlich Equation decreased as concentration increased. This was described using the Sibbesen modification of the Freundlich Equation. This modification was then included in competition Equations. For both the selenite–phosphate and the arsenate–phosphate data, competition was not ‘symmetrical’, that is, the competition terms were not reciprocals of each other. We think this occurred because competition between ions is not only competition for adsorption sites but also involves electrical effects that follow penetration of the surface.
Antonio A S Alfaya - One of the best experts on this subject based on the ideXlab platform.
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use of rice straw as biosorbent for removal of cu ii zn ii cd ii and hg ii ions in industrial effluents
Journal of Hazardous Materials, 2009Co-Authors: Crystian Goncalves Rocha, Dimas Augusto Morozin Zaia, Reni Ventura Da Silva Alfaya, Antonio A S AlfayaAbstract:Abstract Adsorption experiments were carried out using waste rice straw of several kinds as a biosorbent to adsorb Cu(II), Zn(II), Cd(II) and Hg(II) ions from aqueous solutions at room temperature. To achieve the best adsorption conditions the influence of pH and contact time were investigated. The isotherms of adsorption were fitted to the Freundlich Equation. Based on the experimental data and Freundlich model, the adsorption order was Cd(II) > Cu(II) > Zn(II) > Hg(II) on the rice straw. This quick adsorption process reached the equilibrium before 1.5 h, with maximum adsorptions at pH 5.0. Thermodynamic aspects of the adsorption process were investigated. The biosorbent material was used in columns for the removal of ions Cu, Zn, Cd and Hg of real samples of industrial effluent and its efficiency was studied.
