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Adsorption

2014

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Articles 1 - 19 of 19

Full-Text Articles in Engineering

Application Of Various Adsorbents To Remove Micro-Pollutants In Aquatic System, Chanil Jung Dec 2014

Application Of Various Adsorbents To Remove Micro-Pollutants In Aquatic System, Chanil Jung

Theses and Dissertations

Untreated or insufficiently treated pharmaceuticals and endocrine disrupting compounds (EDCs) as well as heavy metals have influenced the ecosystem and their exposures in the water system have threatened human health; causing cancers and adverse health effect to immune system. While various water treatment techniques have been applied to solve this problem, adsorption has been considered as one of the most efficient and manageable water purification techniques. Advanced analysis methods for aqueous contaminants have improved comprehension, allowing proficiency about the fate of trace leveled emerging contaminants, thus allowed to reveal the adsorption mechanisms of each pollutant. This dissertation focuses on the …


Treatment Of Synthetic Oil Sands Tailing Water With Activated Carbon, Alfredo Martinez Iglesias Dec 2014

Treatment Of Synthetic Oil Sands Tailing Water With Activated Carbon, Alfredo Martinez Iglesias

Electronic Thesis and Dissertation Repository

The extraction of bitumen from the Canadian tar sands has thus far generated approximately 840 billion liters of oil sands process affected water (OSPW) that is currently being stored in containment ponds. OSPW is known to be acutely toxic to various organisms, due to the presence of naphthenic acids (NAs). The scale and sheer volume of OSPW being stored in tailing ponds have generated serious public concerns. Many emerging technologies have been investigated as treatment options for OSPW reclamation. This work studied the feasibility of using granular activated carbon (GAC) to adsorb several naphthenic acids in a model solution of …


Predictive Model Development For Adsorption Of Organic Contaminants By Carbon Nanotubes, Onur Apul Aug 2014

Predictive Model Development For Adsorption Of Organic Contaminants By Carbon Nanotubes, Onur Apul

All Dissertations

The main objective of the study was to investigate mechanisms and statistical modeling of synthetic organic contaminant (SOC) adsorption by carbon nanotubes (CNTs). First, predictive models were developed for adsorption of low molecular weight aromatic compounds by multi-walled carbon nanotubes (MWCNTs) using experimental data for 59 compounds. Quantitative structure-activity relationship (QSAR) and linear solvation energy relationship (LSER) approaches were employed and developed models were externally validated using an independent dataset obtained from the literature. Up to date, no QSAR model has been reported for predicting adsorption of organics by CNTs. No LSER model is available which comprehensively investigates the adsorption …


Adsorption Of Halogenated Aliphatic Contaminants By Graphene Nanomaterials: Comparison With Carbon Nanotubes And Granular Activated Carbons, Yang Zhou Aug 2014

Adsorption Of Halogenated Aliphatic Contaminants By Graphene Nanomaterials: Comparison With Carbon Nanotubes And Granular Activated Carbons, Yang Zhou

All Theses

Graphene nanomaterials are two-dimensional single layer sp2 hybridized carbon atoms densely packed in a hexagonal honeycomb lattice and can be visualized as basic building blocks for fullerenes, carbon nanotubes (CNTs), and graphite. In addition, they are hydrophobic nanomaterials and possess a large specific surface area (SSA), thus they have been evaluated as promising adsorbents to remove synthetic organic compounds (SOCs) from water. As with granular activated carbons (GACs) and CNTs, adsorption behavior of SOCs on graphene depends on the physicochemical properties of the adsorbents (e.g., specific surface area, pore size distribution and surface chemistry), SOCs (e.g., hydrophobicity, molecular size and …


Heavy Metal Desorption From Cement Hydrates Caused By Chloride Solutions, Akihiko Hayashi, Yuko Ogawa, Kenji Kawai Jul 2014

Heavy Metal Desorption From Cement Hydrates Caused By Chloride Solutions, Akihiko Hayashi, Yuko Ogawa, Kenji Kawai

International Conference on Durability of Concrete Structures

After the demolition of concrete structures, it is expected to recycle the whole of the demolished concrete. As of now, however, it is difficult to recycle the fine powders generated in the processes of demolition of concrete and manufacture of recycled aggregate because these powders may contain heavy metals exceeding the soil environmental standard, and such powders are disposed finally. It is well known that heavy metals are easily adsorbed on cement hydrates. To promote the total recycling of demolished concrete, it is important to remove adsorbed heavy metals from the fine powders easily. This article tried to gain a …


In Situ Infrared Study Of The Role Of Peg In Stabilizing Silica-Supported Amines For Co2 Capture, Jak Tanthana, Steven Chuang Jul 2014

In Situ Infrared Study Of The Role Of Peg In Stabilizing Silica-Supported Amines For Co2 Capture, Jak Tanthana, Steven Chuang

Steven S.C. Chuang

The CO(2) capture capacity, adsorption mechanism, and degradation characteristics of two sorbents, silica-supported tetraethylenepentamine (TEPA/SiO(2)) and polyethylene-glycol-modified TEPA/SiO(2) (PEG/TEPA/SiO(2)), are studied by diffuse reflectance infrared Fourier transform spectroscopy and mass spectrometry. The CO(2) capture capacities of TEPA/SiO(2) and PEG/TEPA/SiO(2) are determined to be 2087 and 1110 micromol CO(2) g(-1) sorbent, respectively. Both sorbents adsorb CO(2) as hydrogen-bonding species, NH(2)--O, and carbamate/carboxylate species. The CO(2) adsorption half-time increases with the number of CO(2) capture cycles. Infrared results suggest that the increased adsorption half-time is a result of diffusion limitation, caused by accumulation of TEPA and PEG species on the surface of …


Spectroscopic Investigation Into Oxidative Degradation Of Silica-Supported Amine Sorbents For Co2 Capture, Chakravartula Srikanth, Steven Chuang Jul 2014

Spectroscopic Investigation Into Oxidative Degradation Of Silica-Supported Amine Sorbents For Co2 Capture, Chakravartula Srikanth, Steven Chuang

Steven S.C. Chuang

Oxidative degradation characteristics of silica-supported amine sorbents with varying amounts of tetraethylenepentamine (TEPA) and polyethylene glycol (PEG; P200 or P600 represents PEG with molecular weights of 200 or 600) have been studied by IR and NMR spectroscopy. Thermal treatment of the sorbents and liquid TEPA at 100 °C for 12 h changed their color from white to yellow. The CO2 capture capacity of the TEPA/SiO2 sorbents (i.e., SiO2-supported TEPA with a TEPA/SiO2 ratio of 25:75) decreased by more than 60 %. IR and NMR spectroscopy studies showed that the yellow color of the degraded sorbents resulted from the formation of …


Oxide-Supported Tetraethylenepentamine For Co2 Capture, James Fisher, Jak Tanthana, Steven Chuang Jul 2014

Oxide-Supported Tetraethylenepentamine For Co2 Capture, James Fisher, Jak Tanthana, Steven Chuang

Steven S.C. Chuang

CO2 capture capacity of tetraethylenepentamine (TEPA) supported on beta zeolite, SiO2, and Al2O3 has been studied by transient flow switching approach and temperature programmed desorption (TPD) technique coupled with diffuse infrared reflectance Fourier transform spectroscopy and mass spectrometry (MS). TEPA/beta zeolite shows the highest CO2 capture capacity. Adsorbed CO2 on TEPA/beta zeolite can be characterized as weakly and strongly adsorbed CO2. The former desorbs when CO2 partial pressure decreases; the latter desorbs during TPD. Strongly adsorbed CO2 is in the form of carbonates interacting with the NH functional groups of TEPA. This interaction caused the NH and CH intensity to …


Modeling The Construction Of Polymeric Adsorbent Media: Effects Of Counter-Ions On Ligand Immobilization And Pore Structure, Enrico Riccardi, Jee-Ching Wang, Athanasios I. Liapis Feb 2014

Modeling The Construction Of Polymeric Adsorbent Media: Effects Of Counter-Ions On Ligand Immobilization And Pore Structure, Enrico Riccardi, Jee-Ching Wang, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Molecular dynamics modeling and simulations are employed to study the effects of counter-ions on the dynamic spatial density distribution and total loading of immobilized ligands as well as on the pore structure of the resultant ion exchange chromatography adsorbent media. The results show that the porous adsorbent media formed by polymeric chain molecules involve transport mechanisms and steric resistances which cause the charged ligands and counter-ions not to follow stoichiometric distributions so that (i) a gradient in the local nonelectroneutrality occurs, (ii) non-uniform spatial density distributions of immobilized ligands and counter-ions are formed, and (iii) clouds of counter-ions outside the …


Removal And Recovery Of Heavy Metals By Nickel Smelter Slag, Maame Kyeiwaa Addai Jan 2014

Removal And Recovery Of Heavy Metals By Nickel Smelter Slag, Maame Kyeiwaa Addai

Electronic Thesis and Dissertation Repository

The research was performed to assess the potential of nickel smelter slag, an industrial waste, as an adsorbent in the removal of heavy metals from solution. Results from batch studies on the effect of pH, metal-slag contact time, particle size, competition by other ions and slag dose were used to estimate the optimum adsorption conditions of the slag as an adsorbent for Cu, Pb, Cd, Ni and Zn. Adsorption of Cu and Pb were akin to the pseudo second order kinetic model and followed the Langmuir adsorption isotherm model. The calculated k2 values were 0.18 mg g-1min …


A Psa Process For An Oxygen Concentrator, Aaron A. Moran Jan 2014

A Psa Process For An Oxygen Concentrator, Aaron A. Moran

ETD Archive

Oxygen is used in a variety of chemical processes and for medical purposes throughout the world. Pressure swing adsorption (PSA) has become a viable alternative to cryogenic distillation for the separation of oxygen from air with the development of advanced adsorbents like zeolites. PSA processes are inherently complex because it is a dynamic process. Efficient operation of a PSA process is necessary in order to utilize the capacity of the adsorbent as much as possible and reduce the power requirements of the process.In this thesis, a novel zeolite adsorbent was utilized in a PSA process for oxygen generation with the …


Effects Of Oxygen Adsorption On The Surface State Of Epitaxial Silicene On Ag(111), Xun Xu, Jincheng Zhuang, Yi Du, Haifeng Feng, N Zhang, Chen Liu, Tao Lei, Jiaou Wang, M Spencer, Tetsuya Morishita, Xiaolin Wang, S X. Dou Jan 2014

Effects Of Oxygen Adsorption On The Surface State Of Epitaxial Silicene On Ag(111), Xun Xu, Jincheng Zhuang, Yi Du, Haifeng Feng, N Zhang, Chen Liu, Tao Lei, Jiaou Wang, M Spencer, Tetsuya Morishita, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

Epitaxial silicene, which is one single layer of silicon atoms packed in a honeycomb structure, demonstrates a strong interaction with the substrate that dramatically affects its electronic structure. The role of electronic coupling in the chemical reactivity between the silicene and the substrate is still unclear so far, which is of great importance for functionalization of silicene layers. Here, we report the reconstructions and hybridized electronic structures of epitaxial 4 3 4 silicene on Ag(111), which are revealed by scanning tunneling microscopy and angle-resolved photoemission spectroscopy. The hybridization between Si and Ag results in a metallic surface state, which can …


A Computational Study Of Carbon Dioxide Adsorption On Solid Boron, Qiao Sun, Meng Wang, Zhen Li, Aijun Du, Debra J. Searles Jan 2014

A Computational Study Of Carbon Dioxide Adsorption On Solid Boron, Qiao Sun, Meng Wang, Zhen Li, Aijun Du, Debra J. Searles

Australian Institute for Innovative Materials - Papers

Capturing and sequestering carbon dioxide (CO2) can provide a route to partial mitigation of climate change associated with anthropogenic CO2 emissions. Here we report a comprehensive theoretical study of CO2 adsorption on two phases of boron, α-B12 and γ-B28. The theoretical results demonstrate that the electron deficient boron materials, such as α-B12 and γ-B 28, can bond strongly with CO2 due to Lewis acid-base interactions because the electron density is higher on their surfaces. In order to evaluate the capacity of these boron materials for CO2 capture, we also performed calculations with various degrees of CO2 coverage. The computational results …


Mixed Surfactant Systems: Thermodynamics And Applications In Metal Oxide Imprinting, Suvid Joshi Jan 2014

Mixed Surfactant Systems: Thermodynamics And Applications In Metal Oxide Imprinting, Suvid Joshi

Theses and Dissertations--Chemical and Materials Engineering

In this work we study mixtures of cationic surfactant (CTAB) and sugar based surfactant(s) (octyl beta-D-glucopyranoside (C8G1), dodecyl maltoside (C12G2) and octyl beta-D-xylopyranoside (C8X1)) to understand the non-ideal thermodynamic behavior of the mixtures of cationic and non-ionic surfactants in water and synthesis of imprinted materials. The thermodynamics of micellization, mixing and dilution of these systems are studied using Isothermal Titration Calorimetry (ITC) and the experimental data obtained are modeled with a pseudo-phase separation model with non-ideal mixing described by regular solution theory. It is shown that a model accounting for enthalpy of demicellization and enthalpy of dilution based on McMillan-Mayer …


The Effects Of Bam As An Adsorptive Media On Phosphorus Removal In Stormwater, Sultan Salamah Jan 2014

The Effects Of Bam As An Adsorptive Media On Phosphorus Removal In Stormwater, Sultan Salamah

Electronic Theses and Dissertations

To maintain the quality of receiving water bodies, it is desirable to remove total phosphorus (TP) in stormwater runoff. Many media filtration technologies have been developed to achieve TP and soluble reactive phosphorus (SRP) removal. Efficient media adsorption is essential to insure control of stormwater phosphorus inputs to the receiving water body. This project develops and analyzes a functionalized Biosorption Media (BAM) to remove phosphorus species from stormwater runoff. One goal of this project is to find the BAM values for coefficients such as maximum adsorption capacity (QM: 4.35E-05) for the media through SRP isotherm equilibrium experiments using the Langmuir …


Volume Swing Frequency Response Method For Determining Mass Transfer Mechanisms In Microporous Adsorbents, Mohammad Iftekhar Hossain Jan 2014

Volume Swing Frequency Response Method For Determining Mass Transfer Mechanisms In Microporous Adsorbents, Mohammad Iftekhar Hossain

Theses and Dissertations

Because of their numerous important applications in industrial catalytic, separation, and purification processes, miroporous materials have attracted considerable attention. Understanding the dynamic behavior of various gases in these porous materials is a critical step in designing, developing and effective operation of such kind of industrial processes. Frequency response (FR) methods have proven to be one of the best recently developed techniques and have been widely used to investigate kinetics behavior of various gas-solid systems due to their ability to discriminate among different rate limiting mechanisms. The current work has been focusing on the development of a volume swing frequency response …


First-Principles Study Of The Electric Field Effect On The Water-Adsorbed Rutile Titanium Dioxide Surface, Abraham L. Hmiel Jan 2014

First-Principles Study Of The Electric Field Effect On The Water-Adsorbed Rutile Titanium Dioxide Surface, Abraham L. Hmiel

Legacy Theses & Dissertations (2009 - 2024)

TiO2 is a semiconducting material that has been used extensively in many industrial applications, and recently has become a candidate for photocatalytic water splitting, fuel cell anode support materials, sensors, and other novel nanodevices. The interface of TiO2 with water, historically well-studied but still poorly understood, presents a ubiquitous environmental challenge towards the ultimate practical usefulness of these technologies. Ground-state density functional theory (DFT) calculations studying the characteristics of molecular adsorption on model surfaces have been studied for decades, showing constant improvement in the description of the energetics and electronic structure at interfaces. These simulations are invaluable in the …


Dynamic Analysis Of Dna Nanoparticle Immobilization To Model Biomaterial Substrates Using Combinatorial Spectroscopic Ellipsometry And Quartz Crystal Microbalance With Dissipation, Tadas Kasputis, Alex Pieper, Mathias Schubert, Angela K. Pannier Jan 2014

Dynamic Analysis Of Dna Nanoparticle Immobilization To Model Biomaterial Substrates Using Combinatorial Spectroscopic Ellipsometry And Quartz Crystal Microbalance With Dissipation, Tadas Kasputis, Alex Pieper, Mathias Schubert, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

Gene expression within cells can be altered through gene delivery approaches, which have tremendous potential for gene therapy, tissue engineering, and diagnostics. Substrate-mediated gene delivery describes the delivery of plasmid DNA or DNA complexed with nonviral vectors to cells from a surface, with the DNA immobilized to a substrate through specific or nonspecific interactions. In this work, DNA-nanoparticle (DNA–NP) adsorption to substrates is evaluated using combinatorial, in situ spectroscopic ellipsometry and quartz crystal microbalance with dissipation (SE/QCM-D), to evaluate the basic dynamic processes involved in the adsorption and immobilization of DNA–NP complexes to substrates. The concentration of DNA–NP solutions influences …


Fluctuations In Transient Response Of Adsorption-Based Plasmonic Sensors, Zeljko D. Cupic Dec 2013

Fluctuations In Transient Response Of Adsorption-Based Plasmonic Sensors, Zeljko D. Cupic

Zeljko D Cupic

The basic parameters of a sensor element defining its ultimate performance are sensitivity and intrinsic noise. In plasmonic gas sensors both are determined by refractive index changes due to adsorption and desorption (a–d) of target analyte particles to the sensor active area. In this paper we present a general model that can be simultaneously used to determine sensitivity and intrinsic noise of a plasmonic sensor both during transients and in steady-state and is valid for multi-analyte environments. The model utilizes the conventional probabilistic approach. It is derived without any assumptions about the stochastic nature of the fundamental (a–d) process. It …