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You searched for subject:(Mineral Surface Reactivity). Showing records 1 – 3 of 3 total matches.

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University of California – Merced

1. Small, Molly Ann. Surface Complexation and Reactivity of Kaolinite and Gibbsite with Cadmium: A multi-method approach.

Degree: Environmental Systems, 2014, University of California – Merced

Determination of energetically favorable surface complexes that form at the mineral-solution interface is important for understanding the surface reactivity of common minerals such as kaolinite and gibbsite and the behavior of toxic pollutants such as Cd2+. In this study, experimental Cd LIII X-ray Absorption Near-Edge Structure (XANES) was combined with periodic density functional theory (DFT), theoretical XANES calculations of the Cd LIII edge, and surface complexation modeling to characterize Cd2+ complexes sorbed to surfaces. Cd LIII spectra were collected for Cd2+ reference compounds, aqueous solutions, and sorption samples. Linear combination fitting of sorption sample XANES spectra was performed with known compounds and a sorption sample spectrum at low Cd surface coverage (IS-Kaol) that was interpreted to represent a mononuclear inner-sphere complex. With increasing surface coverage, spectra showed a systematic decrease in the fraction of IS-Kaol reference, indicating that as surface coverage increases, the proportion of bidentate complexes decreases. In linear combination fits, a component interpreted as a dimeric component (CdAlO4(s) or Cd(OH)2) increased with surface coverage, suggesting that dimerization or surface reformation may be occurring when surface coverage is high. A postulated set of Cd2+ surface reactions on the (100) face of kaolinite and gibbsite were compiled as constrained by DFT calculations and Cd LIII XANES. The Charge Distribution MUlti-SIte Complexation (CD-MUSIC) model was used in PhreePlot with this constrained set of reactions and used to derive complexation constants. Sorption on gibbsite was fit with a mononuclear bidentate reaction at low surface coverage (1 Cd/300 nm2), and with bidentate and dimer reactions at high coverage (1 Cd/3 nm2). Sorption on kaolinite was fit with a bidentate reaction at low surface coverage (1 Cd/150 nm2), and with bidentate, monodentate, and outer-sphere reactions at high surface coverage (1 Cd/1.5 nm2). The results indicate that mononuclear inner-sphere complexes form first on both kaolinite and gibbsite. With increased surface coverage, dimer complexes form on gibbsite, and outer-sphere complexes form on kaolinite, which is consistent with results from linear combination fits.

Subjects/Keywords: Geochemistry; Environmental geology; Cadmium; Gibbsite; Kaolinite; Mineral Surface Reactivity; Surface Complexation Modeling; XANES

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Small, M. A. (2014). Surface Complexation and Reactivity of Kaolinite and Gibbsite with Cadmium: A multi-method approach. (Thesis). University of California – Merced. Retrieved from http://www.escholarship.org/uc/item/27d23358

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Small, Molly Ann. “Surface Complexation and Reactivity of Kaolinite and Gibbsite with Cadmium: A multi-method approach.” 2014. Thesis, University of California – Merced. Accessed October 17, 2019. http://www.escholarship.org/uc/item/27d23358.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Small, Molly Ann. “Surface Complexation and Reactivity of Kaolinite and Gibbsite with Cadmium: A multi-method approach.” 2014. Web. 17 Oct 2019.

Vancouver:

Small MA. Surface Complexation and Reactivity of Kaolinite and Gibbsite with Cadmium: A multi-method approach. [Internet] [Thesis]. University of California – Merced; 2014. [cited 2019 Oct 17]. Available from: http://www.escholarship.org/uc/item/27d23358.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Small MA. Surface Complexation and Reactivity of Kaolinite and Gibbsite with Cadmium: A multi-method approach. [Thesis]. University of California – Merced; 2014. Available from: http://www.escholarship.org/uc/item/27d23358

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. ΣΑΜΑΡΑΣ, ΠΕΤΡΟΣ. ΠΑΡΑΓΩΓΗ ΧΑΡΑΚΤΗΡΙΣΜΟΣ  ΚΑΙ ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ.

Degree: 1995, Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ); Aristotle University Of Thessaloniki (AUTH)

ΟΙ ΣΤΟΧΟΙ ΤΗΣ ΕΡΓΑΣΙΑΣ ΑΥΤΗΣ ΗΤΑΝ ΝΑ ΕΞΕΤΑΣΤΕΙ Η ΔΡΑΣΗ ΤΩΝ ΑΝΟΡΓΑΝΩΝ ΣΥΣΤΑΤΙΚΩΝΣΤΗΝ ΑΝΑΠΤΥΞΗ ΤΗΣ ΠΟΡΩΔΟΥΣ ΔΟΜΗΣ ΚΑΙ ΣΤΗΝ ΤΑΧΥΤΗΤΑ ΑΝΤΙΔΡΑΣΗΣ ΚΑΤΑ ΤΗΝ ΠΑΡΑΓΩΓΗ ΤΩΝ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΜΕ ΤΗΝ ΠΡΟΣΡΟΦΗΤΙΚΗ ΤΟΥΣ ΙΚΑΝΟΤΗΤΑ ΚΑΙ ΝΑ ΑΝΑΠΤΥΧΘΕΙΕΝΑ ΜΑΘΗΜΑΤΙΚΟ ΜΟΝΤΕΛΟ ΠΡΟΣΡΟΦΗΣΗΣ ΣΕ ΣΥΣΚΕΥΕΣ ΑΣΥΝΕΧΟΥΣ ΚΑΙ ΣΥΝΕΧΟΥΣ ΛΕΙΤΟΥΡΓΙΑΣ. ΟΙ ΕΝΕΡΓΟΙ ΑΝΘΡΑΚΕΣ ΠΑΡΑΣΚΕΥΑΣΘΗΚΑΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ ΜΕ ΥΨΗΛΗ ΠΕΡΙΕΚΤΙΚΟΤΗΤΑ ΣΕ ΑΝΟΡΓΑΝΑ ΣΥΣΤΑΤΙΚΑ ΣΕ ΑΤΜΟΣΦΑΙΡΑ CO2 ΓΙΑ ΔΙΑΦΟΡΕΤΙΚΕΣ ΘΕΡΜΟΚΡΑΣΙΕΣ ΚΑΙ ΧΡΟΝΟΥΣ ΠΑΡΑΜΟΝΗΣ. ΕΝΕΡΓΟΙ ΑΝΘΡΑΚΕΣ ΠΑΡΑΧΘΗΚΑΝ ΕΠΙΣΗΣ ΑΠΟ ΛΙΓΝΙΤΗ ΠΟΥ ΥΠΟΒΛΗΘΗΚΕ ΣΕ ΚΑΤΕΡΓΑΣΙΑ ΜΕ ΔΙΑΦΟΡΕΤΙΚΑ ΔΙΑΛΥΜΑΤΑ ΟΞΕΩΝ ΓΙΑ ΤΗΝ ΑΠΟΜΑΚΡΥΝΣΗ ΤΩΝΑΝΟΡΓΑΝΩΝ ΣΥΣΤΑΤΙΚΩΝ. ΣΤΟ ΧΑΡΑΚΤΗΡΙΣΜΟ ΤΗΣ ΠΟΡΩΔΟΥΣ ΔΟΜΗΣ ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΕ Η ΠΡΟΣΡΟΦΗΣΗ Ν2 ΣΤΟΥΣ 77Κ ΚΑΙ CO2 ΣΤΟΥΣ 298 Κ. Η ΑΠΟΜΑΚΡΥΝΣΗ ΤΩΝ ΚΑΤΑΛΥΤΙΚΩΝ ΑΝΟΡΓΑΝΩΝ ΣΥΣΤΑΤΙΚΩΝ ΠΡΟΚΑΛΕΣΕ ΤΗΝ ΕΛΑΤΤΩΣΗ ΤΗΣ ΤΑΧΥΤΗΤΑΣ ΕΝΕΡΓΟΠΟΙΗΣΗΣ ΚΑΙ ΤΗΝ ΠΑΡΑΓΩΓΗ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΜΕΛΕΤΗΘΗΚΕ ΓΙΑ ΤΗΝ ΑΠΟΜΑΚΡΥΝΣΗ ΦΑΙΝΟΛΗΣ, ΦΟΥΛΒΙΚΟΥ ΟΞΕΟΣ ΚΑΙ ΙΟΝΤΩΝ ΑΡΣΕΝΙΚΟΥ ΑΠΟ ΥΔΑΤΙΚΑ ΔΙΑΛΥΜΑΤΑ. (ΠΕΡΙΚΟΠΗ ΠΕΡΙΛΗΨΗΣ)

THE OBJECTIVES OF THIS WORK WERE TO EXAMINE THE EFFECT OF MINERAL MATTER ON THEPORE STRUCTURE DEVELOPMENT AND THE REACTION RATE DURING THE PRODUCTION OF ACTIVATED CARBONS, TO INVESTIGATE THE RELATIONSHIP BETWEEN THE PHYSICO-CHEMICAL PROPERTIES OF ACTIVATED CARBONS AND THEIR ADSORPTION CAPACITY AND TO DEVELOP A MATHEMATICAL MODEL THAT DESCRIBES ADSORPTION ON ACTIVATED CARBON COLUMNS. ACTIVATED CARBONS PRODUCED FROM GREEK LIGNITE WITH A HIGH MINERAL MATTER CONTENT UNDER VARIOUS EXPERIMENTAL CONDITIONS USING CO2 AS OXIDING AGENT. REMOVAL OF INORGANIC IMPURITIES WAS ACCOMPLISHED BY ACID WASHING OF RAW LIGNITE WITH DIFFERENT ACID SOLUTIONS. ACTIVATED CARBONS WERE ALSO PRODUCED FROM ACID TREATED LIGNITE WITH DIFFERENT ASH CONTENT. FOR THE CHARACTERIZATION OF ACTIVATED CARBONS ADSOPTION OF N2 AT 77 K AND CO2 AT 298K WAS USED. REMOVAL OF INORGANIC IMPURITIES BROUGHT ABOUT A LOWERING IN REACTIVITY AND AN INCREASE IN THE MICROPORE SURFACE AREA OF ACTIVATED CARBONS. ADSORTION STUDIES WERE PERFORMED IN ORDER TO EVALUATE THE EFFICIENCY OF VARIOUS ACTIVATED CARBONS TO REMOVE TOXIC SUBSTANCES FROM WATER. TWO ORGANIC AND ONE ORGANIC SUBSTANCE WERE USED. THESE WERE PHENOL, FULVIC ACID AND ARSENIC IONS. THE ADSORPTIVE CAPACITY OF ACTIVATED CARBONS DEPENDED PRIMARILY ON THE ASH CONTENT AND THE COMPOUND. (ABSTRACT TRUNCATED)

Subjects/Keywords: Activated carbon; ADSORPTION COLUMNS; ADSORPTION MODEL; ADSORTPIONCAPACITY; MINERAL MATTER; Porosity; Reactivity; SURFACE AREA; ΑΝΟΡΓΑΝΑ ΣΥΣΤΑΤΙΚΑ; ΕΙΔΙΚΗ ΕΠΙΦΑΝΕΙΑ; Άνθρακας, Ενεργός; ΚΛΙΝΗΣ ΠΡΟΣΡΟΦΗΣΗΣ; ΜΑΘΗΜΑΤΙΚΟ ΜΟΝΤΕΛΟ ΠΡΟΣΡΟΦΗΣΗΣ; Πορώδης δομή; ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ; ΤΑΧΥΤΗΤΑ ΕΝΕΡΓΟΠΟΙΗΣΗΣ

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

ΣΑΜΑΡΑΣ, . (1995). ΠΑΡΑΓΩΓΗ ΧΑΡΑΚΤΗΡΙΣΜΟΣ  ΚΑΙ ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ. (Thesis). Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ); Aristotle University Of Thessaloniki (AUTH). Retrieved from http://hdl.handle.net/10442/hedi/3356

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

ΣΑΜΑΡΑΣ, ΠΕΤΡΟΣ. “ΠΑΡΑΓΩΓΗ ΧΑΡΑΚΤΗΡΙΣΜΟΣ  ΚΑΙ ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ.” 1995. Thesis, Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ); Aristotle University Of Thessaloniki (AUTH). Accessed October 17, 2019. http://hdl.handle.net/10442/hedi/3356.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

ΣΑΜΑΡΑΣ, ΠΕΤΡΟΣ. “ΠΑΡΑΓΩΓΗ ΧΑΡΑΚΤΗΡΙΣΜΟΣ  ΚΑΙ ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ.” 1995. Web. 17 Oct 2019.

Vancouver:

ΣΑΜΑΡΑΣ . ΠΑΡΑΓΩΓΗ ΧΑΡΑΚΤΗΡΙΣΜΟΣ  ΚΑΙ ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ. [Internet] [Thesis]. Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ); Aristotle University Of Thessaloniki (AUTH); 1995. [cited 2019 Oct 17]. Available from: http://hdl.handle.net/10442/hedi/3356.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

ΣΑΜΑΡΑΣ . ΠΑΡΑΓΩΓΗ ΧΑΡΑΚΤΗΡΙΣΜΟΣ  ΚΑΙ ΠΡΟΣΡΟΦΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΕΝΕΡΓΩΝ ΑΝΘΡΑΚΩΝ ΑΠΟ ΕΛΛΗΝΙΚΟ ΛΙΓΝΙΤΗ. [Thesis]. Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ); Aristotle University Of Thessaloniki (AUTH); 1995. Available from: http://hdl.handle.net/10442/hedi/3356

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

3. Kurganskaya, Inna. A multi-scale approach to study silicate dissolution: Kinetic Monte Carlo simulations and experimental observations.

Degree: PhD, Natural Sciences, 2013, Rice University

Dissolution of silicate minerals is an important part of many geological processes taking place on Earth’s surface as well as in the deep crust. Weathering of rocks and soil formation, metasomatic rock alteration by hydrothermal fluids, and diagenetic transformation of sediments are controlled by dissolution reactions. Secondary pore space of natural reservoirs can be significantly altered by dissolution and the subsequent precipitation of clay minerals. As a consequence, the potential storage capacity of natural fuels, carbon dioxide, or radioactive waste, can be affected. In addition, the stability of rocks hosting potentially hazardous materials largely depends on their dissolution rates. The development of computational ab initio and Molecular Dynamics techniques drives the interest to study dissolution reactions at the molecular scale. At the same time, advanced microscopic techniques allow us to study dissolution process at the nm to micron scale and investigate spatio-temporal variations of surface reactivity. The combination of these methods has great potential for tackling fundamental questions of the mechanisms of mineral dissolution. My thesis work presents an integrated multiscale approach to studying the dissolution of silicates. The work consists of three main parts: experimental studies of the dissolving mineral surface at the micron scale, Kinetic Monte Carlo (KMC) simulations at the nanometer scale, and the parametrization of KMC models by ab initio derived activation energies. Muscovite mica and quartz were chosen as template study objects. These two minerals represent “2-dimentional” (phyllosilicates) and 3-dimentional (tectosilicates) crystal structures of silicates as well as “complex” and “simple” chemical bond networks. The first part of my muscovite dissolution studies is based on experimental observations of the reacted surface with vertical scanning interferometry. We quantified the distribution of surface reactivity in terms of surface roughness and mean height levels and also measured the dissolution rate. Additional investigations of the detailed surface structure were done by using atomic force microscopy. KMC simulations of muscovite dissolution constitute the second part of this work. We developed KMC models that simulate the dissolution of mica structures. We varied the number of the basic reaction types in the system and achieved a satisfying match between modeling results and experimental observations. Also, we showed how KMC methods can be used as a tool for testing my hypotheses regarding the role of surface reactions on the overall reaction mechanism. The third part of the work is dedicated to the problems of complexity and parametrization of KMC models. Here, we present four KMC models of quartz dissolution that vary by their complexity level. The capabilities of the models to predict experimentally observed dissolution features were shown for prism, rhombohedral, and pinacoid quartz faces. The simulation results demonstrate the role of the topological state in the recognition… Advisors/Committee Members: Luttge, Andreas (advisor), Dasgupta, Rajdeep (committee member), Whitmire, Kenton H. (committee member), Sawyer, Dale S. (committee member).

Subjects/Keywords: Mineral dissolution; Dissolution kinetics; Crystal dissolution; Kinetic Monte Carlo; Monte Carlo; Stochastic simulations; Silicates; Computer simulations; Multiscale; VSI; Optical Interferometry; Surface roughness; Dissolution rate; Sheet silicates; Phyllosilicates; Mica; Quartz; Muscovite; Surface topography; Surface reactivity; Site topology; Stepwave model; Kinematic stepwave; Etch pit; Etch hillock; Mica edge; Crystallographic control; Model complexity; Model parameterization; Geochemistry

…analysis of reacted solvent composition and microscopic observations of the mineral surface. The… …the information about reactivity distribution over the surface is critically important for… …mineralwater interface was shown to substantially influence on surface reactivity by stabilizing the… …controls, as well as predicting surface structure and reactivity at the scales from nanometers to… …Luttge A. (2008) Interferometric study of pyrite surface reactivity in acidic… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kurganskaya, I. (2013). A multi-scale approach to study silicate dissolution: Kinetic Monte Carlo simulations and experimental observations. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/77190

Chicago Manual of Style (16th Edition):

Kurganskaya, Inna. “A multi-scale approach to study silicate dissolution: Kinetic Monte Carlo simulations and experimental observations.” 2013. Doctoral Dissertation, Rice University. Accessed October 17, 2019. http://hdl.handle.net/1911/77190.

MLA Handbook (7th Edition):

Kurganskaya, Inna. “A multi-scale approach to study silicate dissolution: Kinetic Monte Carlo simulations and experimental observations.” 2013. Web. 17 Oct 2019.

Vancouver:

Kurganskaya I. A multi-scale approach to study silicate dissolution: Kinetic Monte Carlo simulations and experimental observations. [Internet] [Doctoral dissertation]. Rice University; 2013. [cited 2019 Oct 17]. Available from: http://hdl.handle.net/1911/77190.

Council of Science Editors:

Kurganskaya I. A multi-scale approach to study silicate dissolution: Kinetic Monte Carlo simulations and experimental observations. [Doctoral Dissertation]. Rice University; 2013. Available from: http://hdl.handle.net/1911/77190

.