Ozone Consumption by Aquatic Fulvic Acids as precursors of Radical-type Reaction

摘要

In the presence of OH-radical scavenger (t-butyl alcohol t-BuOH, HCO_3-, Ch_3COOH at 10~-2M), the relative ozoen consumption increases as relative ozone dose, pH and UV-absorbance of fulvic acid respectively increase. In the absence of OH-radical scavenger, the relative ozone consumption was found significnatly higher, whatever the reaction pH is (between 2.5 and 7.5_. However, it appears duirng he first stage of reaction, the effect of OH-radical scavenger is not preponderant until pH is above 4 as we already mentionned in a previous paper. The presence of such precursors was shown in this study by means of spcific analysis after ozonation of a fulivc acid at acidic pH, it's a question of hydrogen peroxide and glyoxalic acid at concentrations of about some hundred micrograms per litre.