Statistical Study of Instantaneous Demand of para-Chlorobenzoic Acid as an Ozone/Hydroxyl Radical Probe Compound

Nien-Hsin Kao, Ming-Chien Su
2009 Environmental Engineering Science  
Ozone dissolution is a chain reaction process due to ozone decomposition which generates hydroxyl radicals that can be detected by using pCBA ( para-Chlorobenzoic Acid) as a probe compound. However, reported reactions for pCBA and OH radicals have not been sufficiently described statistically to show its permanence. In order to investigate this, two different stages of batch experiments were conducted to study the reactions among generated OH radicals, pCBA and t-butanol. In addition, an
more » ... aneous demand, plus rapid and gradual phases of reactions for pCBA were also observed in this study. This study attained a cause-and-effect linear empirical correlation equation between degraded pCBA and ozone concentration, which indicated chain reactions generating OH radicals. The significance of correlation is confirmed by conducting a two-tailed hypothesis test. Additionally, due to free available OH radicals in the set conditions, an instantaneous demand of probe compound was confirmed by using the goodness-of-fit test. Observed instantaneous demand was about 83 to 55% for the initial concentration ratios of pCBA to ozone being 0.160 to 0.232, respectively. Calculated pseudofirstorder rate constants for pCBA are from 1.345 to 4.677 min À1 and 0.218 to 0.944 min À1 for rapid and gradual degradation phases, respectively.
doi:10.1089/ees.2008.0131 fatcat:e5652lwpmfderfiivbx3et7wia