Matching Items (3)
- All Subjects: Water
- Genre: Academic theses
- Genre: Masters Thesis
- Creators: Olson, Larry
- Member of: ASU Electronic Theses and Dissertations
The purpose of drinking water regulations is to keep our drinking water safe from contaminants. This research reviewed federal regulation including the Contaminant Candidate List (CCL) regulatory process, the public health effects of six nitrosamines in drinking water, analyzes of occurrence data from Unregulated Contaminant Monitoring Rule (UCMR 2) and suggests how nitrosamines can be regulated. Currently only total trihalomethanes (THM) and haloacetic acids (HA) are regulated at the federal level. However, California has notification action levels and Massachusetts has guidelines of 10 ng/L for nitrosamine concentration. Nitrosamine data collected under the UCMR 2 were analyzed to assess the occurrence and the effect of disinfectant type and source water type. The data showed that N-nitrosodimethylamine (NDMA) was detected in drinking water at concentrations higher than the minimum reporting level (MRL) of 2 ng/L. Four nitrosamines including N-nitroso-diethylamine (NDEA), N-nitroso-di-n-butylamine (NDBA), N-nitroso-methylethylamine (NMEA) and N-nitroso-pyrrolidine (NPYR) and very low detections. N-nitroso-di-n-propylamine (NDPA) was not detected in the sample analyses. NDMA was primarily detected in public water systems using chloramines other than chlorine.
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.
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.