Reaction kinetics and efficiencies for the hydroxyl and sulfate radical based oxidation of artificial sweeteners in water.

Over the past several decades, the increased use of artificial sweeteners as dietary supplements has resulted in rising concentrations of these contaminants being detected in influent waters entering treatment facilities. As conventional treatments may not quantitatively remove these sweeteners, radical-based advanced oxidation and reduction (AO/RP) treatments could be a viable alternative. In this study, we have established the reaction kinetics for both hydroxyl ((•)OH) and sulfate (SO(4)(•-)) radical reaction with five common artificial sweeteners, as well as their associated reaction efficiencies. Rate constants for acesulfame K, aspartame, rebaudioside A, saccharin, and sucralose were <2 × 10(7), (2.28 ± 0.02) × 10(9), (2.1 ± 0.1) × 10(8), <2 × 10(7), and (1.7 ± 0.1) × 10(8) M(-1) s(-1) for the sulfate radical, and (3.80 ± 0.27) × 10(9), (6.06 ± 0.05) × 10(9), (9.97 ± 0.12) × 10(9), (1.85 ± 0.01) × 10(9), and (1.50 ± 0.01) × 10(9) M(-1) s(-1) for the hydroxyl radical, respectively. These latter values have to be combined with their corresponding reaction efficiencies of 67.9 ± 0.9, 52.2 ± 0.7, 43.0 ± 2.5, 52.7 ± 2.9, and 98.3 ± 3.5% to give effective rate constants for the hydroxyl radical reaction that can be used in the modeling of the AOP based removal of these contaminants.

PrioNet Canada: a network of centres of excellence for research on prion diseases--ongoing and future research directions.

It is PrioNet's vision to build a network that shapes and sustains prion research in Canada, translating basic science into accessible socioeconomic benefits for global betterment. PrioNet's research is developing surveillance measures, diagnostic tools, vaccines, and potential therapies and determining the various impacts of prion diseases on people. PrioNet seeks to integrate scientifically informed risk management strategies and to use this knowledge to address ongoing problems posed by bovine spongiform encephalopathy (BSE), the gathering crisis of chronic wasting disease (CWD), emerging issues of human prion disease, and basic scientific understanding of the nature of prions. PrioNet is strategically responding to prion threats by focusing its network of highly accomplished researchers and trainees to implement integrated risk management strategies that could not be supported by other mechanisms.

Prionet Canada: a network of centres of excellence for research into prions and prion diseases.

PrioNet Canada's strength in basic, applied, and social research is helping to solve the food, health safety, and socioeconomic problems associated with prion diseases. Prion diseases are transmissible, fatal neurodegenerative diseases of humans and animals. Examples of prion diseases include bovine spongiform encephalopathy (BSE, commonly known as "mad cow" disease), Creutzfeldt-Jakob disease in humans, and chronic wasting disease (CWD) in deer and elk. As of March 31, 2008, PrioNet's interdisciplinary network included 62 scientific members, 5 international collaborators, and more than 150 students and young professionals working in partnership with 25 different government, nongovernment, and industry partners. PrioNet's activities are developing strategies based on a sustained, rational approach that will mitigate, and ultimately control, prion diseases in Canada.