Carlos A. Guzman-Perez - Department of Chemical and Biological Engineering, University of Saskatchewan, ۵۷ Campus Drive, Saskatoon, SK, S۷N ۵A۹ Canada
Jared Robertson - Department of Chemical and Biological Engineering, University of Saskatchewan, ۵۷ Campus Drive, Saskatoon, SK, S۷N ۵A۹ Canada
Jafar Soltan - Department of Chemical and Biological Engineering, University of Saskatchewan, ۵۷ Campus Drive, Saskatoon, SK, S۷N ۵A۹ Canada

The influence of adsorption on micropollutant removal by ozonation catalyzed by alumina was investigated using atrazine and 2,4-D as model micropollutants. Catalyst performance in removing these two endocrine disrupting compounds was examined in a laboratory-scale mixed reactor using a catalyst dose of 8 g L-1 at acidic and neutral pH levels. While atrazine did not exhibit affinity for alumina adsorption, a notable uptake of 2,4-D was observed during adsorption on alumina. Addition of alumina in atrazine and 2,4-D ozonation processes resulted in an increase of ozone decomposition into hydroxyl radicals, which led to an increase in the initial rate of micropollutant removal. However, in the case of atrazine, the micropollutant removal rate was dramatically affected by the presence of a radical scavenger, whereas ozonation of 2,4-D catalyzed by alumina exhibited significantly higher rates when compared with the non-catalytic ozonation process. The results of the present study indicate that micropollutant adsorption plays a major role in the ozonation process catalyzed by alumina, thus counteracting the inhibiting effects of radical scavengers.

Ozone; Catalytic Ozonation; Alumina; Atrazine; 2,4-D; Water treatment