Matching Items (3)
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- All Subjects: Environmental health
- Genre: Masters Thesis
- Creators: Olson, Larry
- Creators: Cadillo – Quiroz, Hinsby
- Creators: Green, Matthew
- Resource Type: Text
Description
United States Environmental Protection Agency (USEPA) had identified and recommended air quality monitoring to take place at 63 schools throughout the country. Unfortunately, tribal schools were not considered during the time USEPA conducted the analysis. The importance of identifying any air toxic pollutants affecting school children needs to be analyzed. Conducting an air monitoring toxic analysis on the Navajo Nation at Church Rock Elementary School, Church Rock, New Mexico (CRNM) was carried out. The current school location posed a concern, in regards to the surrounding stationary, mobile, and natural emissions emitted all types of toxic pollutants. USEPA sponsors various air monitoring program, which Tribal Air Monitoring Support (TAMS) program undertook, and offered tribal programs, organizations or agencies to utilized air monitoring equipment's. The air monitoring setup was conducted with the contract Eastern Research Group, Inc. (ERG) laboratory, where collection of 24-hour ambient air samples for 60 days on a 6-day sampling interval were performed. The analysis for volatile organic compounds (VOCs)were collected from canister samples using USEPA Compendium Method TO-15, polycyclic aromatic hydrocarbons (PAHs) from polyurethane foam (PUF) and XAD-2 resin samples using USEPA Compendium Method TO-13A. Carbonyl compounds were collected by sorbent cartridge samples using USEPA Compendium Method TO-11A, and trace of metals from filters were sampled using USEPA Compendium Method IO-3.5 and FEM EQL-0512-202. A total of 53 VOC concentrations were greater than 1 μg/m3, where dichlorodifluoromethane, trichlorofluoromethane, chloromethane, dichloromethane, propylene, toluene, acrolein and acetylene were detected. A total of 23 carbonyl compound concentrations were greater than 1 μg/m3, where acetone and formaldehyde were measured. Naphthalene average with the highest average for PAHs, where phenanthrene and retene were the second and third highest averages. As for the metals the highest averages resulted from manganese, chromium and lead. Overall, the air toxic pollutants resulted from CRNM surrounding monitoring site were detected. Identifying the potential emitter source or sources cannot be assessed.
ContributorsBilley, Karmen (Author) / Olson, Larry (Thesis advisor) / Peterson, Danny (Committee member) / Brown, Albert (Committee member) / Arizona State University (Publisher)
Created2015
Description
High-Density polyethylene (HDPE) is the most used polymer on earth. Since it is used in such large quantities, it has become the most extensively produced polymer on the planet. Unfortunately, the rate of reusing or recycling HDPE is far behind the rate of production leading to plastic pollution. Most of this waste plastic ends up in landfills or incineration to recover energy. Plastic production consumes a lot of energy and is associated with CO2 emissions. This method of disposing plastic only adds to the environmental pollution rather than improving it. Primary reasons for low recycling rate appear to be more political and financial. In the US, the rate of recycling was less than 10% whereas Japan showed a recycling rate of more than 80%. The other aspect of low recycling is financial. In order to make recycling a financially viable process, efforts have to be made to streamline the process of waste collection, segregation and technically feasible process. This study focusses on the technical aspect of the issue. Even though efforts have been made to recycle HDPE, none of the processes have been recycle HDPE with financial viability, recovering full value of plastic, minimum CO2 emissions and minimum change in properties of the polymer. This study focusses on effective recycling of HDPE with minimum change in its properties. Dissolution has been used to dissolve the polymer selectively and then reprecipitating the polymer using a non-solvent to obtain the polymer grains. This is followed by mixing additives to the polymer grains to minimize degradation of the polymer during the extrusion process. The polymer is then extruded in an extruder beyond its melting temperature. This process is repeated for 5 cycles. After each cycle, the polymer is tested for its properties using the Tensile Testing, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Dynamic Mechanicalii
Analysis (DMA). It was observed that the rheological properties of the polymer were maintained after the 5th recycle whereas the mechanical properties deteriorated after the 2nd recycle. Also, increase in carbonyl index was observed after 5th recycle.
ContributorsSaini, Rahul Rakesh (Author) / Green, Matthew (Thesis advisor) / Holloway, Julianne (Committee member) / Xie, Renxuan (Committee member) / Arizona State University (Publisher)
Created2022
Description
Zero-Valent Metals (ZVM) are highly reactive materials and have been proved to be effective in contaminant reduction in soils and groundwater remediation. In fact, zero-Valent Iron (ZVI) has proven to be very effective in removing, particularly chlorinated organics, heavy metals, and odorous sulfides. Addition of ZVI has also been proved in enhancing the methane gas generation in anaerobic digestion of activated sludge. However, no studies have been conducted regarding the effect of ZVM stimulation to Municipal Solid Waste (MSW) degradation. Therefore, a collaborative study was developed to manipulate microbial activity in the landfill bioreactors to favor methane production by adding ZVMs. This study focuses on evaluating the effects of added ZVM on the leachate generated from replicated lab scale landfill bioreactors. The specific objective was to investigate the effects of ZVMs addition on the organic and inorganic pollutants in leachate. The hypothesis here evaluated was that adding ZVM including ZVI and Zero Valent Manganese (ZVMn) will enhance the removal rates of the organic pollutants present in the leachate, likely by a putative higher rate of microbial metabolism. Test with six (4.23 gallons) bioreactors assembled with MSW collected from the Salt River Landfill and Southwest Regional Landfill showed that under 5 grams /liter of ZVI and 0.625 grams/liter of ZVMn additions, no significant difference was observed in the pH and temperature data of the leachate generated from these reactors. The conductivity data suggested the steady rise across all reactors over the period of time. The removal efficiency of sCOD was highest (27.112 mg/lit/day) for the reactors added with ZVMn at the end of 150 days for bottom layer, however the removal rate was highest (16.955 mg/lit/day) for ZVI after the end of 150 days of the middle layer. Similar trends in the results was observed in TC analysis. HPLC study indicated the dominance of the concentration of heptanoate and isovalerate were leachate generated from the bottom layer across all reactors. Heptanoate continued to dominate in the ZVMn added leachate even after middle layer injection. IC analysis concluded the chloride was dominant in the leachate generated from all the reactors and there was a steady increase in the chloride content over the period of time. Along with chloride, fluoride, bromide, nitrate, nitrite, phosphate and sulfate were also detected in considerable concentrations. In the summary, the addition of the zero valent metals has proved to be efficient in removal of the organics present in the leachate.
ContributorsPandit, Gandhar Abhay (Author) / Cadillo – Quiroz, Hinsby (Thesis advisor) / Olson, Larry (Thesis advisor) / Boyer, Treavor (Committee member) / Arizona State University (Publisher)
Created2019