Treatment of Cryptosporidium and Dye Contaminants Using Photoelectrocatalytic Oxidation.

摘要

Water quality is a major concern of the United Nations and the World Health Organization (WHO). Contaminated surface and ground water sources and poorly functioning water distribution systems contribute to transmission of waterborne contaminants (Braghetta, 2006). Worldwide, 1.8 million people die yearly from diarrheal disease (WHO, 2004). Even with regulations and improved treatment methods, waterborne contaminants continue to be present. For the past 30 years, waterborne outbreaks in the United States are a result of emerging infectious diseases caused by microorganisms in the aquatic environment.;Not all water concerns are based on microbial contaminants and their associated outbreaks. With increase in production and the manufacturing of goods that require synthetic dyes comes an increase of the presence of these dyes in environments outside of the manufacturing process. Demand for synthetic dyes accounts for 7x10 5 metric tons of dyestuffs produced every year (Sahasivam, 2006), and upwards of 15% of that dye accounts as waste for non-production use (Daneshvar, 2005).;Researchers continue to explore methods to provide the highest quality of water. Advanced oxidation processes (AOP) are beneficial for treating contaminants typically not removed, disinfected, or inactivated by conventional water treatment processes such as biological or physical-chemical technologies. This dissertation compares the inactivation of Cryptosporidium parvum oocysts by PCO, PECO, electrolysis, and UV reactors; the first order inactivation rate constants for PECO, PCO, electrolysis, and ultraviolet irradiation were 1.0 x 10-2 +/- 1.6 x 10-3 sec -1 , 3.4 x 10-3 +/- 3.2 x 10-4 sec-1 , 3.3 x 10-3 +/- 3.0 x 10 -3 sec-1 , and 1.8 x 10-3 +/- 3.2 x 10-3 sec-1 respectively. Additionally, investigation regarding the degradation of tartrazine (FD&C Acid Yellow No. 23) and erioglaucine (FD&C Acid Blue No. 5), by comparing operational parameters of recirculation rate, tartrazine concentration, chloride ion concentration, and applied bias voltage by treatment with PECO were also explored. For both tartrazine and erioglaucine, the recirculation rate of 4.1 L/min, applied voltage = 9V, chloride ion concentration = 100 mg/L, and dye concentration (tartrazine = 12.0 mg/L, erioglaucine = 10 mg/L) achieved degradation rates of k = 0.006 +/- 0.0004 min-1 and 0.0173 +/- 0.00004 min-1 respectively.