| The presence of pharmaceutically active compounds (PhACs) in aquatic systems is an emerging environmental issue and poses a potential threat to ecosystems and human health. Unfortunately, current water treatment techniques do not efficiently remove all of the PhACs which results in the occurrence of such compounds in surface and ground waters. Advanced oxidation/reduction processes (AO/RPs) which utilize the oxidizing hydroxyl radical (·OH) and reducing hydrated electron (e-aq), to directly degrade chemical contaminants are alternatives to traditional water treatment methods.;Cholesterol-lowering pharmaceuticals (fibrate and statins) were chosen for these studies as they are among the most frequently prescribed pharmaceuticals for reducing human blood cholesterol. These pharmaceuticals have been detected as contaminants in numerous waters.;This dissertation reports the absolute bimolecular reaction rate constants for these pharmaceutical compounds, clofibric acid, bezafibrate and gemfibrozil, atorvastatin, fluvastatin, pravastatin, simvastatin and lovastatin, with the hydroxyl radical and hydrated electron. Transient spectra were obtained for the intermediate radicals produced by the hydroxyl radical reactions. In addition, preliminary degradation mechanisms and major products were elucidated using 137Cs gamma-irradiation and LC-MS. These data are required for evaluating the potential use of AO/RPs for the destruction of these compounds in treating water for various purposes.;Additionally, the fluorescence behavior of two statin pharmaceuticals, atorvastatin and fluvastatin, was investigated and it was suggested that due to the high sensitivity and selectivity of fluorescence spectroscopy, this technique may be an alternative approach to online monitoring and control of pharmaceutical compounds in water intended for reuse.;Lastly, the indirect photochemical behavior of atorvastatin, the most prescribed drug in the world, in simulated natural waters was investigated. Indirect photochemical pathways include reaction of compounds with singlet oxygen (1DeltaO2), hydroxyl radical (· OH), and photoexcited organic matter (3DOM* ). The bimolecular reaction rate constant for the reaction of atorvastatin with singlet oxygen and hydroxyl radical were evaluated. Experiments were performed in a solar simulator and a UV (300--400 nm) reactor. From this data the percent contribution of hydroxyl radical and singlet oxygen to the photodegradation of atorvastatin was determined. |
