Gamma irradiation for disinfection of water and wastewater
Abstract
Physical disinfectants have emerged in recent years as viable alternatives to conventional chlorination. The recent emphasis on developing alternative disinfectants has come about as a result of concern over disinfection by-products (DBP), and the resistance of some protozoan pathogens to conventional disinfectants. The purpose of this research was to investigate the applicability of $\gamma$ radiation as a disinfectant for (waste)water treatment by quantifying microbial dose-response of important pathogens, investigating induced toxicity and mutagenicity, and performing modeling of a $\gamma$-disinfection reactor. The results of these experiments validate the technical feasibility of using $\gamma$ irradiation for disinfection at water and wastewater treatment facilities. Furthermore, $\gamma$ irradiation has displayed superior characteristics in terms of DBP production, as measured in terms of both effluent toxicity (Ceriodaphnia dubia assay) and mutagenicity (Ames assay) tests as compared to chlorine disinfection of the same samples. Two cylindrical $\gamma$ radiation disinfection chambers were modeled based on achieving a minimum of five logs of Escherichia coli inactivation. Despite the technical feasibility and potential advantages in terms of DBPs, $\gamma$ irradiation with $\sp{60}$Co is an order of magnitude more expensive than chlorine or ultraviolet disinfection. Because of this, $\gamma$ irradiation is unlikely to be applied with this source. However, the prospect of using recycled radioactive waste from nuclear power plants could alter the economic argument dramatically, and finding a productive use for these "wastes" was a primary motivating factor in conducting this research.
Degree
Ph.D.
Advisors
Blatchley, Purdue University.
Subject Area
Civil engineering|Sanitation
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