A complex mixture of industrial effluents was treated under
ozonation and only 45% COD removal was achieved. In this
process, there is not a significant dependence of COD or color
with pH in the range of 3-7. A significant COD removal improvement
(∼80%) was reached when iron plates were added to the
ozonation process. Unlike ozonation alone, catalyzed ozonation at
acidic pH is initially faster than that at pH7. At the end of treatment,
however, pH 7 results in a higher %COD removal (∼80%).
This is an advantage since no additives are necessary to carry out the process. The iron catalyzed ozonation does not lead to
the production of important amounts of sludge at any pH in
the range of 3-7, and this represents another advantage of the
evaluated process here since the raw sewage possessed an
initial pH of 7.4.