Abstract
In this study the effect of ozone and peroxone on the structure of Hymenolepis nana eggs at different pH (5, 7 and 10) was evaluated. Experiments were conducted with an ozone dose of 1.1 mg/min for 60 min; peroxone tests were done with the same conditions of ozonation process plus 0.33 mL of 33% hydrogen peroxide. Studies with scanning and transmission electron microscopy did not show ultrastructural changes after the treatment with ozone and peroxone at pH 5 and 7, but at pH 10 the eggs lost their external layer, making them more vulnerable.