Environmental Chemistry Commons^™

Using Slow-Release Permanganate Candles To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson, Ann Kambhu, Steve D. Comfort

School of Natural Resources: Faculty Publications

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI survey maps to guide direct push groundwater sampling. A TCE plume (100-600 µg L^-1) was identified in a low permeable silty-clay aquifer (K_h = 0.5 …

Chemical Properties Of Forest Soils In The Catskills Region, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Differential Protein Expression In Polystichum Acrostichoides Due To Metal Exposure, Paul Alexander Ilkanich, Pratheek C. Koneru

Undergraduate Research Posters 2012

Plants are considered the most cost effective and environmentally sound way to clean up the soils and water contaminated with toxic metals. We focused our studies on the fern species Polystichum acrostichoides. A total of 17 protein spots were up regulated and 3 proteins were down regulated upon various metal exposures, and are arranged to be subjected to liquid chromatography-tandem mass spectrometry for further identification.

Preparation Of Copper-Based Oxygen Carrier Supported On Titanium Dioxide, Yaowen Cui

Masters Theses & Specialist Projects

Chemical-looping combustion is an indirect oxygen combustion strategy, considered to be the most cost-effective power generation technology with the CO2 inherently concentrated. In this process, a solid oxygen carrier is used to transfer oxygen from the air reactor to the fuel reactor, which completely isolates nitrogen in air to meet with fuels. The oxygen carriers in the combustion process are subjected to the severe environments, such as high temperatures, multi-cycle operations, and thermodynamic limitations. Thus, the preparation of an oxygen carrier with high durability and better kinetics under harsh environment could be an essential part of Chemical-looping combustion development. In …

Removal Of Heavy Metals From Drinking Water By Adsorption Onto Limestone With A Focus On Copper And Aluminum Applications, Swarna Latha Somasani

Masters Theses & Specialist Projects

Elevated levels of arsenic and other heavy metals like copper, aluminum, zinc, and selenium in drinking water are found to have deleterious effects on human health. Hence, finding methods for reducing their levels is critical. Iron-coated limestone is used as an adsorption material for the removal of heavy metals from drinking water. Removal of heavy metals by native or uncoated limestone was also observed and used for comparison to and evaluation of the improvement in removal efficiency from the ironcoated material. The removal efficiency with limestone was studied for different concentrations of heavy metals. Kinetic studies were done to determine …

Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman

Chemistry Faculty Publications

The reaction of an isomeric mixture of the methyl perfluoroalkyl ether, C4F9OCH3 (Novec-7100), in the presence of isopropyl alcohol (IPA) and/or water has been studied by measuring the rate of product formation using an ion-selective electrode (ISE) for fluoride ion, Karl Fisher coulometric titrations for water, and 1H and 19F NMR spectroscopy for product identification and rate studies. The results showed the methyl perfluoroalkyl ether to be very stable with products forming at the rate of ∼1 ppm per year at a laboratory temperature of 20 °C. Measurements over the temperature range of 6° to 100 °C were made on …

Synthesis Of 1,1-Dialkyhydrazines And Their Hydroxyl Radical Degradation In Aqueous Environments, Benjamin F. Strong

Masters Theses

Determination of hydroxyl radical rate constants are essential to ensure adequate degradation of contaminants in wastewater. Hydrazines are an important class of organic contaminants and are the focus of this research. Ten 1,1-dialkylhydrazines are synthesized by the zinc reduction of the corresponding N-nitrosamines. Their hydroxyl radical rate constants are determined using the linear accelerator at the Notre Dame Radiation Laboratory at pH 4, 7, and 10.

Their rate constants are found to depend on the protonation state of the molecule. At pH 4 the molecules are fully protonated and hydrogen atom abstraction is favored from the alkyl chains. At …

Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay

Graduate Theses and Dissertations

The following dissertation describes synthetic efforts toward the synthesis of the C21-C34 fragment of antascomicin B. Our initial enzymatic approach is detailed as well as an asymmetric transfer hydrogenation (ATH) strategy that will be used in the eventual total synthesis of the molecule. Several investigations into anomalies observed during (ATH) reactions are also discussed.

Recovery Of Sensitive Watersheds In The Northeastern United States From Chronic Acidification: The Role Of Soil Chemistry, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Mercury Transportation In Soil Using Gypsum From Flue Gas Desulphurization Unit In Coal-Fired Power Plant, Kelin Wang

Masters Theses & Specialist Projects

This work investigates mercury flux in soil amended by gypsum from flue gas desulphurization (FGD) units of coal-fired power plants. There are two phases of this research, including field and greenhouse studies. Previous studies indicate that FGD gypsum could increase corn yield, but may lead to more mercury uptake by corn.

Recent studies have been carried out in greenhouses to investigate mercury transport in FGD gypsum treated soil. Major aspects include uptake of mercury by plants and emission of mercury into the atmosphere based on application rates of FGD gypsum. Additional aspects include rainfall, temperature, soil, and plants types. Higher …

Global Estimates Of Mineral Dust Aerosol Iron And Aluminum Solubility That Account For Particle Size Using Diffusion-Controlled And Surface-Area-Controlled Approximations, Qin Han, Charles S. Zender, J. Keith Moore, Clifton S. Buck, Ying Chen, Anne Johansen, Christopher I. Measures

All Faculty Scholarship for the College of the Sciences

Mineral aerosol deposition is recognized as the dominant source of iron to the open ocean and the solubility of iron in the dust aerosol is highly variable, with measurements ranging from 0.01–80%. Global models have difficulty capturing the observed variations in solubility, and have ignored the solubility dependence on aerosol size. We introduce two idealized physical models to estimate the size dependence of mineral aerosol solubility: a diffusion‐controlled model and a surface‐area‐controlled model. These models produce differing time‐ and space‐varying solubility maps for aerosol Fe and Al given the dust age at deposition, size‐resolved dust entrainment fields, and the aerosol …

Concentration Effects And Ion Properties Controlling The Fractionation Of Halides During Aerosol Formation, Marcelo I. Guzman, Richa R. Athalye, Jose M. Rodriguez

Chemistry Faculty Publications

During the aerosolization process at the sea surface, halides are incorporated into aerosol droplets, where they may play an important role in tropospheric ozone chemistry. Although this process may significantly contribute to the formation of reactive gas phase molecular halogens, little is known about the environmental factors that control how halides selectively accumulate at the air-water interface. In this study, the production of sea spray aerosol is simulated using electrospray ionization (ESI) of 100 nM equimolar solutions of NaCl, NaBr, NaI, NaNO(2), NaNO(3), NaClO(4), and NaIO(4). The microdroplets generated are analyzed by mass spectrometry to study the comparative enrichment of …

Enhancement In Degradation Of Environmental Pollutants: Fenton Degradation Of 2,4,6-Trinitrotoluene And Photodegradation Of Deepwater Horizon Crude Oil, Sarah M. King

LSU New Orleans Theses and Dissertations

Pollution poses serious threats to both the environmental and the organisms that depend on their environment for survival. Due to the toxicity of most contaminants, there is a dire need for remediation of polluted sites. Remediation studies were conducted on two high priority pollutants: 2,4,6-trinitrotoluene (TNT) and crude oil.

TNT was the most common explosive used in the 20^th century. Continuous contamination has resulted in an urgent need for remediation. Fenton reagent provides an advanced oxidation process that is capable of remediating recalcitrant explosives, such as TNT. One drawback of Fenton chemistry is that the reaction requires acidic pH …

Analysis Of Biodiesel Quality Using Reversed Phase High-Performance Liquid Chromatography, Kellyann M. Murphy

Pomona Senior Theses

The alternative fuel biodiesel is produced from the transesterification of vegetable oils or animal fat to fatty acid methyl esters. Pomona has a reactor on campus that can be used to run this reaction and produce biodiesel. The use of biodiesel has been found to lower air pollutant and greenhouse gas emissions, but can be potentially harmful to the engines if it contains impurities. This paper proposes a method using high-performance liquid chromatography to test the quality of biodiesel. This method utilizes instrumentation and materials that are available in Pomona College's Chemistry Department, requires very little sample preparation, and is …

Removal Of Heavy Metals Using Modified Limestone Media: Zinc And Cadmium, Keerthy Mandadi

Masters Theses & Specialist Projects

Heavy metal contamination is a serious concern throughout the world. Increased concentrations in drinking water have many negative impacts on human health. Limestone is an inexpensive and simple media for removing high concentrations of heavy metals from drinking water supplies. Ferric based media is commonly used to remove zinc, cadmium, lead, arsenic and other heavy metals. The drinking water standards set by the US EPA for cadmium, zinc and arsenic are 0.005 mg/L, 5 mg/L and 0.010 mg/L respectively. Bangladesh, parts of India, China and the United States have high concentrations of arsenic in drinking water. Although many technologies exist …

Reducing Lead And Selenium From Drinking Water Using Limestone-Based Material, Sindhu Tumati

Masters Theses & Specialist Projects

Contamination of drinking water with metals is a major problem facing many areas of United States and the World. There is a need for an inexpensive remediation technology for the removal of metals in drinking water that can be applied to small rural water systems. This research will focus on the development of a process for removal of select metals from drinking water by limestone-based material. Metals in drinking water considered for this research include lead and selenium. Limestone-based material has demonstrated the potential to reduce select metals (lead, cadmium and arsenic) in drinking water, with the additional benefit of …

Biologically-Derived Dye-Sensitized Solar Cells: A Cleaner Alternative For Solar Energy, Erika S. Falsgraf

Pomona Senior Theses

This project employs the biological compounds hemin, melanin, and retinoic acid as photoactive dyes in dye-sensitized solar cells (DSSCs). These dyes are environmentally and economically superior to the standard ruthenium-based dyes currently used in DSSCs because they are nontoxic and widely available. Characterization by linear sweep voltammetry yielded averaged maximum overall conversion efficiency values of 0.059% for retinoic acid, 0.023% for melanin, and 0.015% for hemin. Absorption spectra of hemin and retinoic acid suggest that they would complement each other well when used in tandem in one cell because hemin has a secondary maximum absorption peak at 613nm and retinoic …

Arsenic Contamination In Groundwater In Vietnam: An Overview And Analysis Of The Historical, Cultural, Economic, And Political Parameters In The Success Of Various Mitigation Options, Thuy M. Ly

Pomona Senior Theses

Although arsenic is naturally present in the environment, 99% of human exposure to arsenic is through ingestion. Throughout history, arsenic is known as “the king of poisons”; it is mutagenic, carcinogenic, and teratogenic. Even in smaller concentrations, it accumulates in the body and takes decades before any physical symptoms of arsenic poisoning shows. According to the World Health Organization (WHO), the safe concentration of arsenic in drinking water is 10 µg/L. However, this limit is often times ignored until it is decades too late and people begin showing symptoms of having been poisoned.

This is the current situation for Vietnam, …

Toxicity Of Tio₂ Nanoparticles In The Genomic Dna Of Cucurbita Pepo, Fabiola Moreno-Olivas^, Vincent Gant, Isaac Montes, Hiram Castillo-Michel, Kyle L. Johnson, Jose R. Peralta-Videa, Jorge L. Gardea-Torresdey*

COURI Symposium Abstracts, Spring 2012

The nanomaterial industry is growing very fast and nanoparticles (NPs) are used in variety of instruments and goods. NPs can reach the plants through different manners; though, little is known about their impact on food crops and the possible effects in the food chain are unknown. In this research, the possible genotoxic effects of TiO₂ NPs on zucchinis (Cucurbita pepo) were studied. Seven-day old hydroponically grown zuchinnis plants were treated for 7 days with TiO₂ NPs suspended in the nutrient solution at concentrations varying from 0 to 50 mg/L. Random amplified polymorphic DNA assay was performed and showed the …

Impact Of Cerium Oxide Nanoparticles On Cilantro (Coriandrum Sativum), Ana C. Barrios^, Maria I. Morales, Cyren M. Rico, Jose R. Peralta, Jorge L. Gardea-Torresdey

COURI Symposium Abstracts, Spring 2012

The impact of nanoparticles (NPs) on edible plants is currently a theme of great concern. Cerium oxide NPs (CeO₂ NPs) are widely used in biomedical applications, fuel additives, and other consumer products. Studies have shown that these NPs are associated with liver damage. In addition, studies from our research group have also shown that CeO₂ NPs are stored in plant tissues without modification. Thus, these NPs could be distributed in the food chain through edible plants, posing a threat for human health. Cilantro (Coriandrum sativum) is a very important culinary and medicinal plant worldwide. It is …