Environmental Engineering Commons^™

Advanced Buffer Materials For Indoor Air Co₂ Control In Commercial Buildings, Pavithra Ethi Rajan

Masters Theses

"The following describes a novel passive approach to control the indoor CO₂ levels in enclosed spaces, primarily focusing on commercial buildings. Amine impregnated silica sorbents were identified as suitable candidates and synthesized; the amine loading ratio was varied to create a range of materials. These samples along with other commercial zeolite candidates have been tested over a range of CO₂ concentrations to determine the CO₂ adsorption capacity in laboratory systems and under simulated room conditions. The research work also focuses on the CO₂ desorption capacity of the candidate adsorbents. The desorption is allowed to occur gradually …

Phosphorus Removal Using Titanium Dioxide Nanoparticles In Wastewater Treatment, Suyoung Choi Mr.

Theses and Dissertations (Comprehensive)

Due to eutrophication caused by nutrients such as phosphorus (P), local surface water near military garrisons and camps has been deteriorated for several years in the Republic of Korea. Thus, in order to remove excessive P in local fresh water, various size of titanium dioxide (TiO₂) were used.

In the first investigation, TiO₂ mixed bulk powder (particle size > 5µm) showed maximum P removal with pH dependence (higher pH shows lower P removal), that was approximately 27%. To determine adsorption isotherms, Langmuir and Freudlich models were used. The experimental data was better fit by a Langmuir model compared …

Quantum Mechanical Modeling Of Organic-Oxide Surface Complexation Reactions, Brianna Datti

Honors Scholar Theses

Recent advancements in agriculture, industry, and pharmaceutical formulations have increased the presence of organic contaminants in the environment. It is important and necessary to study and understand the processes which control the environmental fate and transformation of contaminants and improve removal and remediation techniques. The use of advanced quantum mechanical modeling is a promising technique to better understand the mechanisms of adsorption within the environment. Relative Gibbs free energy values of adsorption have been calculated using such modeling for selected organic acids sorption to iron oxides, revealing the thermodynamic favorability of each of the reactions, except one involving bidentate mononuclear …

Aqueous Zinc Removal Using Nanoparticle Treated Natural Fibers, Daniel Zieske

Graduate Theses & Non-Theses

The objective of this thesis research is to evaluate and enhance a recently developed water treatment technology. The technology was previously successful in removing airborne mercury from coal fired power plant flue gas, and has since been demonstrated to remove aqueous copper and cadmium. The technology uses natural coconut fibers impregnated with metal nanoparticles using a proprietary technique. A series of batch tests determined that both the treated and untreated natural fibers were capable of removing over 90% of aqueous zinc from a synthetic solution made by dissolving ZnCl2 salts in deionized water. Further testing with a bench scale continuous …

Color Removal From Pulp Mill Effluent Using Coal Ash Produced From Georgia Power Coal Combustion Plants, Christopher B. Willett

College of Graduate Studies: Theses & Dissertations

Two environmental concerns currently face Georgia: coal fly ash (CFA) waste from coal power plants, and the effluent generated by pulp mills. Pulp mill effluent discolors surface waters into which it is discharged, and has been proven to negatively impact the dissolved oxygen and carbon necessary for aquatic life. The proposed solution is a cost-effective adsorption treatment using an inexpensive but abundantly available waste material: CFA. CFA possesses beneficial properties that allow it to effectively remove contaminants, and is available at significantly reduced cost. The primary research objective was to define treatment parameters that would result in the maximum removal …

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 …

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 …

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 …

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 …

Removal Of N-Nitrosodimethylamine And Trihalomethane Precursors With Powdered Activated Carbon, Wilson Beita Sandi

All Theses

N-nitrosodimethylamine (NDMA) has been used commercially in several applications, including the production of liquid rocket fuel, and a variety of foods, but gained more relevance when it was discovered as a drinking water disinfection by-product (DBP) in 1989. NDMA is a probable human carcinogen with 10-6 lifetime cancer risk associated with a drinking water concentration of 0.7 ng/L, and is listed as a priority pollutant in the Code of Federal Regulations; no federal maximum contaminant level has been established for drinking water yet. However, the United States Environmental Protection Agency is planning to make a preliminary regulatory determination in 2013 …

Understanding Formation And Transport Of Amorphous Iron Oxyhydroxides In Porous Media Using Microfluidic Flow Cells- A Novel Method To Study Freshwater Iron Cycling, Neha A. Ghaisas

Master's Theses

The ground water and surface water interface (GSI or Hyporheic zone) is a spatially- and temporally-fluctuating biogeochemical transition zone connecting these two distinct hydrological components. The mixing zone is characterized by a near neutral pH, ambient temperature and a sharp oxygen concentration which in turn has deep impact on the iron cycling and thus the fate of contaminants in the water column. We constructed an experimental micromodel that to observe key processes that affect biogeochemical iron cycling in the fresh water interface zones where the oxic surface water mixes with Fe (II) rich underlying ground water. The flow cell was …

Applied And Mechanistic Studies Of Microbial 17beta-Estradiol Degradation, Zhongtian Li

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The presence of natural estrogens, a class of endocrine disrupting compounds, in water has caused increasing concerns over their adverse impacts on the health of aquatic eco-systems and human beings. In this study, adsorption characteristics of two natural estrogens, 17β-estradiol (E2) and estrone (E1), on granular activated carbon (GAC) were investigated in isotherm tests and in a GAC column. The GAC column was then converted to a biologically active carbon (BAC) column and the removal efficiency of E2 and its primary biodegradation intermediate E1 were monitored. During BAC operation, the impacts of various reactor operation parameters, such as the carbon …

Separation Of Humic Matter From Groundwater Via Anion Exchange Resin: Comparison Of Bead And Powder Form, Sandra June Everett

Open Access Theses & Dissertations

This work describes a comparison of a bead and powder form of anion exchange resin for removing humic matter from groundwater. The materials and procedures described herein involve a manufactured dry humic matter and two forms of the same anion exchange resin. Spectroscopy was the chosen procedure for analysis of organics.

Preliminary experiments were required to gain a better understanding of the materials and to prepare the best conditions for actual experimental research. Five concentrations of humic acid were used for experimental purposes at 0.5, 1, 5, 10 and 20 mg/L. Three concentrations of resin were used: 500, 750 and …

The Effects Of Physical Factors On The Adsorption Of Synthetic Organic Compounds By Activated Carbons And Activated Carbon Fibers, Hatice Kose

All Theses

Activated carbons (ACs) and activated carbon fibers (ACFs) have been extensively used for the removal of synthetic organic compounds (SOCs) that have been found to be toxic, carcinogenic, mutagenic or teratogenic. Adsorption of these compounds on ACs and ACFs are controlled by both physical factors and chemical interactions, which depend on the characteristics of the adsorbent (surface area, pore size distribution (PSD), and surface chemistry), the nature of the adsorbate (molecular weight and size, functional groups, polarity, solubility), and the condition of the background solution (pH, temperature, presence of competitive solutes, ionic strength). Since there are several mechanisms that can …

Modeling Phosphate Adsorption For South Carolina Soils, Jesse Cannon

All Theses

Eroded sediment and the pollutants it transports are problems in water bodies in South Carolina (SC) and the United States as a whole. Current regulations and engineering practice attempt to remedy this problem by trapping sediment according to settling velocity, and thus, particle size. However, relatively little is known about most eroded soils. In most cases, little experimental data are available to describe a soil's ability to adsorb a pollutant of interest. More-effective design tools are necessary if design engineers and regulators are to be successful in reducing the amount of sediment and sediment-bound pollutants in water bodies. This study …

Removal Of Boron From Produced Water By Co-Precipitation / Adsorption For Reverse Osmosis Concentrate, Imran Yusuf Rahman, Yarrow Nelson, Tryg Lundquist

Master's Theses

Co-precipitation and absorption methods were investigated for removal of boron from produced water, which is groundwater brought to the surface during oil and natural gas extraction. Boron can be toxic to many crops and often needs to be controlled to low levels in irrigation water. The present research focused on synthetic reverse osmosis (RO) concentrate modeled on concentrate expected from a future treatment facility at the Arroyo Grande Oil Field on the central coast of California. The produced water at this site is brackish with a boron concentration of 8 mg/L and an expected temperature of 80°C. The future overall …

Adsorption Of Lead (Ii) Ions By Organosilicate Nanoporous Materials, Larry Keith Isaacs

Civil & Environmental Engineering Theses & Dissertations

As-synthesized organosilicate nanoporous (OSNP) materials HMS (hexagonal mesoporous structure) and MCM-41 were used as adsorbents for removal of lead (II) ions in laboratory batch and column studies. Mesoporous organosilicates were prepared from tetraethylorthosilicate (TEOS) and either an ionic (cetyltrimethyl-ammonium) or neutral (dodecylamine) surfactant. Batch reaction distribution coefficients for MCM-41 were K_D = 51.5 L/g (SD = 26.3) at 24 h and K_D = 73.7 L/g (SD = 40.5) at 7 d. OSNP lead (II) ion adsorption increased from pH = 3 until pH ca. 7.5 after which a sharp decrease in adsorption was noted. OSNP materials reflected a …

Heavy Metal Adsorption On Iron Oxide And Iron Oxide-Coated Silica : Macroscopic, Spectroscopic, And Modeling Studies, Ying Xu

Dissertations

To accurately model metal mobility and bioavailability in soils and sediments, systematic sorption studies are needed using representative and well-characterized minerals. Two important surfaces are iron oxide and silica, which are ubiquitous and associated with one another in the environment playing important roles in metal distribution. The objectives of this research are to develop models for predicting speciation and mobility of toxic trace metal ions in groundwater, soils, and sediments when competing ions are present. A model system for soils and sediments, iron oxide-coated silica, was synthesized; the degree of coatings was highly sensitive to the particle size of silica …

Adsorption Capabilities Of Adsorbents For Selected Toxic Air Pollutants, Richard Michael Vaccaro

Theses

The relative adsorption capacities of seven toxic, volatile organic air pollutants of either proven or suspected carcinogenic potential were tested on various adsorbents. Tests were run at flow velocities similar to those set in field sampling. This allows for extrapolation of test results to actual ambient air sampling systems. Experimentation was performed using a gas chromatograph (G.C.) equipped with a flame ionization detector. Sample introduction was carried out using the "displacement method" where the sample is introduced to the adsorbent cartridge as a plug.

Incipient elution volumes (V_N), normalized for bulk adsorbent packing volume, were obtained at various …