| To meet the increasing demand for potable water, reuse and reclamation projects must be developed and implemented to augment water sources. The reuse of treated wastewater could provide a significant portion of the demand for clean water. Although there are many issues concerning the quality and safety of wastewater before it can be reused, the concerns can be broken down into two major categories: microbial and chemical contamination. Pathogenic organisms such as Cryptosporidium and Giardia pose a potential threat to public health. C. parvum oocysts can withstand many typical disinfection processes, particularly chlorine-based systems (LeChevallier and Norton, 1996). Typically, the chlorine dose was increased to eliminate the pathogens but there is a trade off in treatment strategies. Eliminating the biological contaminants with large doses of chlorine compounds the DBP problem, while minimizing the DBP formation requires reduced rates of chlorine, leading to a larger population of microorganisms.; The goal of this research was to develop a catalytic ultrasonic technology for the treatment of wastewaters. As ultrasonic waves travel through a liquid medium, hydroxyl radical are produced (OH•). The OH• is a powerful oxidation agent that can react with a wide spectrum of soluble organic chemicals and can also render bacteria and protozoan pathogens inactive. Additionally, the extreme temperatures and pressures along with the shock wave caused during cavitation bubble collapse can exert great forces on the pathogens and cause impairment. Various ultrasonic frequencies and combinations of frequencies were tested and a tri-frequency ultrasonic reactor was built. It was demonstrated that the ultrasonic process was an effective disinfection technology. The need for chemical additions (i.e. chlorine) is eliminated, solving the problem of disinfection by-product (DBP) formation associated with standard disinfection processes.; In addition to the inactivation of the pathogenic protozoa, improved qualification and quantification methodology was developed to improve efficiency over existing methods. Specifically, a microscope system to allow simultaneous UV and visible light excitation was developed. |
