Kinetics of the ozonation of muconic acid in water.

The removal of muconic acid (specifically trans-trans-butanedioc acid) with ozone from water has been studied for kinetics purposes. Concentrations of muconic acid of 4.4x10(-4)M are completely removed with ozone in less than 14 and 9 min at pH 3 and 7, respectively, and 3x10(-4)M of ozone in the gas. The positive influence of pH was due to the more reactive muconic acid dissociated form with ozone. The process can be described as a second order irreversible gas-liquid reaction developing in the moderate kinetic regime of absorption. At the experimental conditions investigated no free radical reactions are present and muconic acid is entirely oxidized by molecular ozone. Rate constants of the direct reaction between muconic acid and ozone were found to be 1.6x10(4) and 1.4x10(5)M(-1)s(1) at 20 degrees C, pH 3 and 7, respectively, according to film theory.