the competition between the by-products and parent pollutant for OH radical consumption which shows an inhibitory effect, according to Lu et al. [35] and Chan [36]. This conclusion is also supported by the pseudo-first order rate constants values which
decrease with the increase of NB initial concentration, as it was presented in Table 4. Consequently, when t* 1/2 < t1/2, the competition leads to an inhibitory effect, whereas when t* 1/2 > t1/2 there is no competition and a catalytic effect occurred, inducing the increase of NB oxidation rate. When t*1/2 = t1/2(intersection point) the reaction rate does not modify.