关键词: 电解, 臭氧, 乙酸, 效率, 酸性废水

Abstract:

Establishment of an ozone-based advanced oxidation process (AOPs-O₃) for effective treatment of acid wastewater is an important and difficult task. The process of ozonation coupled with electrolysis (electrolysis-ozonation, E-O₃) has been reported to effectively degrade pollutants in neutral solution. We studied the efficiency of E-O₃ for degradation of acetic acid (HAc, an ozone inert chemical) in acid solution and found that E-O₃ had high oxidative efficiency at pH less than 3. For example, 52.2% of 100 mg·L^-1 HAc could be removed by E-O₃ in 120 min at pH 1.0, but only 2.2% and 3.5% by electrolysis and ozonation, respectively. Although the efficiency of E-O₃ decreased with the increase of acidity of solution, it still remained relatively high even at pH 0. An aromatic compound of acetophenone could also be effectively degraded by E-O₃ at pH 1.0. The results indicate that electrons can transfer from cathode to dissolved ozone or oxygen in acidic solution, thus resulting in generation of reactive species, e.g. hydroxyl radicals. A real acidic wastewater was also effectively pretreated by E-O₃. This study provides a promising AOPs-O₃ for treatment of acid wastewaters.

Key words: electrolysis, ozone, acetic acid, efficiency, acid wastewater