Related Experiment Video
Updated: Jan 25, 2026

Determining Viral Disinfection Efficacy of Hot Water Laundering
Published on: June 21, 2022
Chlorinated Cyanurates in Drinking Water: Measurement Bias, Stability, and Disinfectant Byproduct Formation
David G Wahman1, Matthew T Alexander2, Alison G Dugan2
1United States Environmental Protection Agency, Office of Research & Development, Cincinnati, OH 45268.
Abstract:
Two chlorinated cyanurates, commonly referred to as dichlor (anhydrous sodium dichloroisocyanurate or sodium dichloroisocyanurate dihydrate) and trichlor (trichloroisocyanuric acid) may be approved for use in United States drinking water systems as chlorine sources. One complication with dichlor or trichlor's application in drinking water is that the actual free chlorine concentration in these systems cannot be quantified accurately by currently approved methods. Based on known water chemistry, two hypothesized advantages of dichlor or trichlor use are potential increased residual chlorine stability and decreased regulated disinfectant byproduct (DBP) formation. To inform these practical considerations, the current research investigated measurement bias in N,N-diethyl-p-phenylenediamine (colorimetric and portable parallel analyzer), indophenol, amperometric titration, and amperometric electrode free chlorine methods. In addition, hold studies using a surface water and dosed with either free chlorine only, dichlor, or trichlor provided the first side-by-side comparisons of disinfectant residual stability and regulated DBP formation.
More Related Videos
10:48EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples
Published on: March 28, 2015
07:31Murine Drinking Models in the Development of Pharmacotherapies for Alcoholism: Drinking in the Dark and Two-bottle Choice
Published on: January 7, 2019
Related Concept Videos
Confirmation Biases
Hindsight Biases
Aldehydes and Ketones with Water: Hydrate Formation
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
Cleaning, Sterilization, and Disinfection
Cleaning
The cleaning process usually involves using water with detergents or enzymatic cleaner and removing foreign material from objects and surfaces, including organic material such as body fluids or inorganic material like soil. Cleaning is performed before high-level disinfection and sterilization because foreign materials on the cover of the devices interfere with process...
Bias
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...
Radical Substitution: Allylic Chlorination