Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science,1993

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 198-210).

Most metal ions have negative impacts on pulp mill operations. The concentrations of metal ions on pulp fibers and in washwaters rise significantly with increased wastewater recycling. The development of technology to remove these metal ions requires an understanding of how metal ions are bound to pulp components. It is also desirable to predict distribution of metal ions between the pulp fibers and the washwaters. The adsorption isotherms for eight metal ions (Ca, Ba, Mn, Zn, Pb, Cd, Ni, Na) were measured on bleached and unbleached (brownstock) kraft pulps at neutral pH and temperatures ranging from 25 to 75��C. On bleached pulps, the metal ion adsorption increased rapidly with increasing metal ion concentration in solution and then leveled off. At neutral pH, the adsorption on bleached pulp was stoichiometric to the carboxylate sites, whereas the adsorption on unbleached pulp was not, especially at high metal ion concentration in solution and low temperature. The pH isotherms specify the adsorption isotherms of sodium and calcium on wood pulps as pH ranging from 2.5 to 11.0. The pH isotherms on bleached pulp with only COOH functional groups (pK[subscript a] of 3.77) were saturated at pH 4 and above, whereas those on brownstock pulp with both COOH and PhOH (pK[subscript a] of 10) functional groups increased in two steps, at pH 4 and 8. The brownstock pulp is heterogeneous material. Therefore, only the empirical Freundlich model was applied to the data. To predict the metal ion adsorption on bleached pulps, two fundamental equilibrium models were developed: the multi-component ion exchange and the Donnan equilibrium models. The ion-exchange model better predicts the metal adsorption at neutral pH, whereas the Donnan equilibrium model more accurately predicts the pH isotherms. The adsorption kinetics of Ba����� and Ni����� were measured on wood pulps as a function of mixing speed, initial metal ion concentration, and temperature. The adsorption of metal ions reached equilibrium rapidly. The intraparticle diffusion model, based on first principle with a linear relationship assumption between adsorbed and free metal ion concentration, satisfactorily predicted the adsorption kinetics at low metal ion concentration in solution. / Graduation date: 2001

Graduation date: 1999

Adsorption kinetic data recorded for α-lactalbumin, β-casein, β-lactoglobulin, bovine serum albumin and lysozyme at silianized silica surfaces of low and high hydrophobicity, along with a simple model for adsorption and surfactant-mediated elution of protein, were used to analyze the removal of each protein by sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) at each surface. The model relates resistance to surfactant elution to two rate constants: one governing conversion of removable protein to a nonremovable form (s₁), and one governing removal of protein by the surfactant (k [subscript s]). Elution of each protein from hydrophobic silica with SDS was interpreted as providing information relevant to protein-surface binding strength, or si; i.e., protein-specific differences in removal were a result of SDS adsorption to the surface and displacement of surface-bound protein, as opposed to solubilization driven by SDS binding to the protein. SDS-mediated removal of protein from surfaces of lower hydrophobicity were interpreted as generally proceeding according to a similar, displacement mechanism. The model indicated that data recorded for DTAB-mediated elution at each surface were generally less representative of protein-surface behavior, and more a function of k [subscript s], where differences in surfactant attachment to protein and solubilization appeared to play an important role in protein removal. Under controlled conditions use of the model would allow identification of cases where k [subscript s] in particularly protein specific, and illustrates the point that in such cases surfactant-mediated elution of a protein may reveal little about its surface behavior. / Graduation date: 1996

The effect of pH and ionic strength on the equilibrium adsorptive behavior of β-lactoglobulin onto hydrophobic and hydrophilic silicon surfaces was studied using ellipsometry. Plots of amount adsorbed (μg protein/cm²) as a function of protein concentration (mg/ml) exhibited attainment of plateau values beyond a protein concentration of 0.250 mg/ml. At a given pH and ionic strength, plateau values associated with hydrophobic surfaces were observed to be greater than those associated with hydrophilic surfaces. The Langmuir adsorption isotherm was chosen as the most appropriate model to represent the data and was used to compare results obtained under different experimental conditions. Effects of pH and ionic strength on protein adsorption at hydrophilic surfaces indicate that electrostatics played a major role, while pH and ionic strength effects on adsorption to hydrophobic surfaces reflect a greater importance of nonelectrostatic interactions. / Graduation date: 1991

Thesis (M.S. in chemical engineering)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 20, 2010). "Department of Chemical Engineering and Bioengineering." Includes bibliographical references (p. 63-65).

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xiv, 210 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

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