Water and Wastewater Terms Beginning O

A B C D E F G H I J K L M N O P Q R S T U V W Y Z

Orthotolidine (or-tho-TOL-uh-dine)

Orthotolidine is a colorimetric indicator of chlorine residual. If chlorine is present, a yellow-colored compound is produced. This reagent is no longer approved for chemical analysis to determine chlorine residual.