| The use of ozone, in water treatment, for color removal, taste and odor control, and disinfection has grown dramatically over the past few years. However, the obvious benefits that accrue from ozone usage are also accompanied by some disadvantages. Ozonation of water results in formation of potentially toxic aldehydes; and increase in biodegradability of organic matter, raising concerns of distribution system bacterial regrowth. In addition, the effects of ozonation on properties of natural organic matter are not completely understood. Finally, the impact of ozonation on optimized alum coagulation--an emerging strategy for TOC removal--has not been verified. An attempt to address these water treatment concerns relating to ozone usage was made in this dissertation, by evaluating oxidation effects on a wide range of water sources including river, reservoir, groundwater derived from a variety of geographical locations in the United States. These water sources were characterized by varying alkalinity, DOC, UV absorbance, and molecular weight distribution.; Ozonation resulted in increases in acidity, relative polarity and non-humic content; and decreases in disinfection by-product formation and aluminum binding capacity. Fluorescence quenching was evaluated as a technique for measuring the binding of the functional groups with aluminum, and found to be satisfactory. Multiple regression analysis was used to derive relationships of various water quality and water treatment variables with concentrations ({dollar}mu{dollar}g/l) and yields ({dollar}mu{dollar}g/mg of DOC) of aldehydes, assimilable organic carbon (AOC), and biodegradable organic carbon (BDOC). Satisfactory levels of the coefficient of determination (i.e., r{dollar}sp2{dollar}) were obtained. Biological parameters were monitored across a pilot-scale water treatment facility. Sequential water treatment processes (e.g., flocculation, sedimentation, GAC adsorption) were shown to reduce the concentrations of these constituents to raw water levels.; Optimization coagulation experiments revealed aluminum coagulants (alum) to be marginally more effective than iron (ferric chloride) coagulants. Ozonation significantly interfered with removal of TOC by alum coagulation only at high doses (2 mg ozone/mg DOC). |
