KINETICS OF REACTIONS OF CHLORINE DIOXIDE (OCLO) IN WATER .1. RATE CONSTANTS FOR INORGANIC AND ORGANIC-COMPOUNDS

The kinetics of chlorine dioxide consumption by a wide range of inorga nic and organic compounds, including a comprehensive series of phenols , have been determined using conventional batch-type and stopped-flow methods. In all cases, the rate law was first-order in chlorine dioxid e and first-order in substrate. The methods allowed us to determine se cond-order rate constants over a range from 10(-5) to 10(5) M-1 s-1. M easured rate constants were high for nitrite, hydrogen peroxide, ozone , iodide, iron (11), and, whenever the pH was not very low, for phenol ic compounds, tertiary amines, and thiols. Bromide, ammonia, structure s containing olefinic C=C double bonds, aromatic hydrocarbons, primary and secondary amines, aldehydes, ketones and carbohydrates were unrea ctive under conditions of water treatment. For substrates that are wea k acids, such as phenols, or weak bases, the effect of pH on the react ion rate showed that the rate constants for the deprotonated compounds are much higher than those for the protonated species.