Analytical methods of chlorine and the substances produced by the chlorine treatments

Chlorine is a common chemical widely used for the disinfection of tap water becauseof the strong oxidizing property and the effectiveness in preventing bacterial, viruses andprotozoa infections. In order to understand the features of the chlorine treatment, thefollowing subjects were discussed: Historical remarks on the use of chlorine; Chemistryof chlorine in water; Analytical methods for the residual chlorine in water; Analyticalmethods for the substances produced by the chlorine treatment. Experimental approachesfor the determination of residual chlorine in tap water and their recent progress are alsomentioned. Among them, differential pulse voltammetry is one of the excellent analyticalmethods to monitor a trace amount of residual chlorine in drinking water. Finally, somenew findings on the chlorination were discussed; i. e., the complete removal technique forthe free chlorine from solution, and a kinetic study for the oxidation of a trace elementduring the chlorination process for tap water. Practical needs have led to the developmentof a portable flow injection analysis (FIA) system for the purpose of the on-site andcontinuous monitoring for the free chlorine in environment samples.