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Wastewater generated from agricultural activities and food production is a source of environmental pollution, and its treatment is a challenging technological issue. Ozone gas (O3), and the possibility of associating it with hydrogen peroxide (H2O2), has the potential to remove persistent organic compounds in effluents. In the present work, wastewater from industrial potato processing was characterized, and its treatment with ozone combined with hydrogen peroxide was assessed. The inlet ozone concentration and the flow rate were 84.5 mg L−1 and 62.5 mL min−1, respectively. The promising conditions of temperature, pH, and H2O2/O3 proportion were determined to reduce the chemical oxygen demand, turbidity, and color, according to a central composite rotatable design. The H2O2/O3 proportions were 0.1, 0.3, 0.5, and 0.6. Additionally, the response variables were evaluated as a function of the ozone and hydrogen peroxide treatment time for up to 24 h. The conditions obtained for treating wastewater from industrial potato processing were the following: temperature = 25°C; pH = 3.0, and H2O2/O3 proportion = 0.1. For the water quality parameters adopted, the combination of ozone and hydrogen peroxide was effective at removing color and turbidity. The chemical oxygen demand, color, and turbidity reduction stabilized after 1.16 h, with cumulative applied dosages of ozone and hydrogen peroxide equal to 380 mg L−1 and 35 mg L−1, respectively. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effectiveness of ozone in the control of fungi and the degradation of fumonisins in maize and possible effects on the chemical composition of the product. Two cultivars of hybrid maize (30F53H and AS1581 PRO) were used. Initially, the saturation process of the porous medium with ozone was studied. The incidence of Fusarium verticillioides, Penicillium spp. and Aspergillus flavus; the suitability of ozone to detoxify grains contaminated by fumonisins and possible qualitative changes in the product were evaluated. Ozone was applied at an inlet ozone concentration of 13.5 mg L−1 and flow rate of 1.0 L min−1, in five exposure periods (0, 12, 24, 36, 48 and 60 h). The estimated daily intake of FB by horses from grains subjected to ozonation was obtained. For the hybrid AS1581PRO, the estimated saturation time and concentration were equivalent to 67.34 min and 5.91 mg L−1, respectively. With regard to the hybrid 30F53H, the saturation time and concentration were 41.74 min and 8.72 mg L−1, respectively. Ozone was an effective fungicidal agent. The use of a concentration of 13.5 mg L−1 over a 24 h-treatment led to a reduction of 81.2 and 86.2% in the concentrations of fumonisin B1 and fumonisin B2, respectively. The estimated daily intake of fumonisins was reduced to 17.21 µg kg−1BW per day, corresponding to half of the acceptable daily intake for equines. Ozone did not affect the chemical composition of the grain. Ozone is effective in controlling fungi and as a detoxifying agent in maize contaminated by fumonisins. [ABSTRACT FROM AUTHOR]