## 3 Results and Discussion
### Ozone, Nitro Gas, and Hydrogen Peroxide Concentration in DBD ACP  
Concentrations of ozone, nitrous gases and hydrogen peroxide as the major reactive species in ACP were measured inside the plasma chamber in different time scales (Table 2).  
In DBD ACP, the electromagnetic field splits the O-O bond in oxygen molecule and the resulting oxygen free radical reacts with another oxygen molecule to form ozone [35]. Hydrogen peroxide is derived from the reaction of plasma radicals (OH, O\({}_{2}\)), with water molecules (H\({}_{2}\)O) and molecular oxygen (O\({}_{2}\)) [36]. With increase in ACP treatment time, the concentrations of all the reactive species would be increased. Ozone was the most prevalent reactive species with 600 ppm concentration after 1 min ACP. The concentrations of nitrous gases and H\({}_{2}\)O\({}_{2}\) were increased in 6 and 10 min ACP treatments, in comparison to 1 min ACP. H\({}_{2}\)O\({}_{2}\) had the lowest concentration compared to ozone and nitrous gases. The concentration of H\({}_{2}\)O\({}_{2}\) was doubled and reached 200 ppm after 10 min, compared to that after 1 min ACP treatment. This could be due to the generation of H\({}_{2}\)O\({}_{2}\) by a number of reactions involving several reactive species, during plasma treatment. In the presence of water vapor present in the environment, H\({}_{2}\)O\({}_{2}\) could be generated by several reactions (Equations (10)-(14)) [37; 38].  
\[e+H_{2}O\ \rightarrow\ e+\ `OH+\ `H \tag{10}\]  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**ACP Treatment Time(s)** & **O\({}_{3}\) (ppm)** & **H\({}_{2}\)O\({}_{2}\) (ppm)** & **NO\({}_{x}\) (ppm)** \\ \hline
60–80 & 600 & 100 & 400 \\
360–380 & 675 & 150 & 470 \\ \hline
600–620 & 675 & 200 & 480 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Ozone, nitrous oxides and hydrogen peroxide concentration during ACP treatment.  
Figure 3: Optical emission spectra of DBD ACP operating in air at 34 kV, 3.5 kHz, 5 mm gap.  
\[O\left({}^{1}D\right)+H_{2}O\rightarrow\ \cdot OH+\cdot OH \tag{11}\]  
\[\cdot OH+\ \cdot OH+\ \rightarrow\ H_{2}O_{2} \tag{12}\]  
\[HO_{2}+HO_{2}\rightarrow\ H_{2}O_{2}+O_{2} \tag{13}\]  
\[HO_{2}+H\rightarrow\ H_{2}O_{2} \tag{14}\]  
It is believed that reactions (12) and (13) could be the major reactions involving hydrogen peroxide formation [38]. Hydrogen peroxide could be primarily formed by recombination of hydroperoxyl radicals (Equation (13)) at high oxygen concentrations and low local OH radical concentration [38]. The generation of hydroperoxyl radicals from ozone depletion (Equation (2)) may also have indirectly contributed to H\({}_{2}\)O\({}_{2}\) generation. The concentration of ozone was the same after 6 and 10 min treatments. Degradation rates of DON after 6 and 10 min ACP were not significantly different (\(p\geq 0.05\)). As discussed in Section 3.1, the ozone species possibly played a major role in the degradation of DON and hence, at the same concentration of ozone; after 6 and 10 min ACP treatments, the degradation rates of DON were similar. In previous studies, ozone was identified as the primary contributor for the degradation of mycotoxins [1; 23; 39]. Between 6 and 10 min ACP treatments, the concentration of ozone stayed the same, possibly due to the interaction of ozone with other reactive species present in ACP, to produce new compounds such as NO\({}_{2}\) and HO\({}_{2}\)[38]. Further studies are required to achieve a better insight regarding the role of each of the reactive species in the degradation of each mycotoxin and their possible synergistic effects to degrade mycotoxins.