Matching Items (4)
- All Subjects: Environmental sciences
- Genre: Masters Thesis
- Creators: Olson, Larry
- Resource Type: Text
- Status: Published
Water quality is a severe problem throughout the world. Much available water is contaminated by pathogenic microbes. This project reviews the traditional process of solar water disinfection in bottles (SODIS), discusses experiments conducted with SODIS bottles modified to thermally enhance the process, analyzes experimental data for modified SODIS containers, and suggests ways that by which the traditional process can be improved. Traditional SODIS is currently used in many rural parts of developing countries to disinfect water. The process uses ultraviolet rays and thermal effects to inactivate microorganisms that tend to cause diarrheal disease. If a sufficiently high temperature is attained to reach a synergistic UV-thermal effect range, the process of SODIS is about three times faster. However, many factors can inhibit attainment of sufficient heating of water in SODIS bottles in practice. By modifying the bottles to enhance effectiveness of sunlight in increasing the temperature of the water, SODIS can be more effective. In this research, a series of experiments were conducted over a period of four months and15 days at Arizona State University Polytechnic campus in Mesa, Arizona, U.S.A. Four different types of inexpensive materials (black paint, white paint, foam insulation, and aluminized mylar) were used individually or in combination in seven different modified configurations to assess the potential of the modifications to increase the temperatures of water inside 2-liter PET bottles. Experiments were run in triplicate. Temperatures inside the bottles, along with yard temperature, were recorded over time. Graphs were plotted for each set of experiments. The results of these experiment show that several types of modifications increased water temperature during exposure to sunlight. Water in bottles with black paint and foam insulation on the back side attained the highest temperatures, approximately 8-10 degrees Celsius above temperatures attained in plain bottles. The results of these experiments show how several inexpensive, easily obtained materials can significantly enhance the SODIS process.
Pharmaceutical and Personal Care Products (PPCPs) are a large, diverse group of emerging contaminants comprised of pharmaceuticals, plasticizers, detergents, and insecticides. Studies have shown that PPCPs are entering aquatic environments, wastewaters, and water supplies. The occurrence of these PPCPs has generated concern resulting in proposed federal legislation that could require control, monitoring, and treatment of Pharmaceutical and Personal Care Products by Publicly Owned Treatment Works (POTWs). This study evaluated the potential financial impact this proposed legislation could have on U.S. POTWs using City of Mesa, Arizona as a model POTW. The current laws concerning PPCPs as well as the proposed legislation were described. The proposed federal legislation would create investigational studies about PPCPs. The studies could lead to regulations concerning the control, monitoring, and treatment of PPCPs by POTWs. The potential financial costs of the following strategies were assessed: multiple barriers concept for PPCP control or prevention programs by POTWs, PPCP monitoring of wastewater, and upgrading POTW treatment technology for PPCP removal. Study results found no new wastewater treatment technologies were economically suitable for POTWs, however, community education and programs such as Household Take-back programs could be financially viable.
The Toledo Core Based Statistical Area (CBSA) presents an interesting case study for the new sulfur dioxide (SO2) one hour standard. Since no SO2 monitor within 75 miles to estimate the attainment status of the area, American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was used in this study to predict potential problems associated with the newly revised standard. The Toledo CBSA is home to two oil refineries, a glass making industry, several coal fired lime kilns, and a sulfuric acid regeneration plant, The CBSA 3 has coal fired power plants within a 30 mile radius of its center. Additionally, Toledo is a major Great Lakes shipping port visited by both lake and ocean going vessels. As a transportation hub, the area is also traversed by several rail lines which feed four rail switching yards. Impacts of older generation freighters, or "steamers", utilizing high sulfur "Bunker C" fuel oil in the area is also an issue. With the unique challenges presented by an SO2 one hour standard, this study attempted to estimate potential problem areas in advance of any monitoring data being gathered. Based on the publicly available data as inputs, it appears that a significant risk of non-attainment may exist in the Toledo CBSA. However, future on-the-books controls and currently proposed regulatory actions appear to drive the risk below significance by 2015. Any designation as non-attainment should be self-correcting and without need for controls other than those used in these models. The outcomes of this screening study are intended for use as a basis for assessments for other mid-sized, industrial areas without SO2 monitors. The results may also be utilized by industries and planning groups within the Toledo CBSA to address potential issues in advance of monitoring system deployment to lower the risk of attaining long term or perpetual non-attainment status.
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.