Abstract
This research aims at optimizing the effects of processing conditions, salts, natural organic materials, and water matrices quality on the effectiveness of the Fe(II)/K2S2O8/hydroxylamine process in the degradation of pararosaniline. Assisting the Fe(II)/KPS (potassium persulfate) treatment with protonated hydroxylamine (H3NOH+) increases the degradation rate of pararosaniline by more than 100%. Radical scavenger experiments show that the SO4?- radical dominates pararosaniline degradation in the Fe(II)/KPS system, whereas (OH)-O-? is the dominant reactive species in the presence of H3NOH+. The disparity in pararosaniline removal effectiveness upon the Fe(II)/KPS/H3NOH+ and Fe(II)/KPS systems gets more significant with increasing reactants doses (i.e., H3NOH+, H2O2, Fe(II)) and solution pH (2-7). Interestingly, H3NOH+ increased the working pH to 6 instead of pH 4 for the Fe(II)/KPS process. Moreover, mineral anions such as Cl-, NO3-, NO2-, and SO4- (up to 10 x 10(-3) m) do not affect the efficiency of the Fe(II)/KPS/H3NOH+ process. In contrast, acid humic decreases the performance of the process by approximate to 20%. In natural mineral water, treated wastewater, and river water samples, the Fe(II)/KPS/H3NOH+ process maintains higher degradation performance (approximate to 95%), whereas the process efficiency is greatly amortized in seawater. The efficiency of the Fe(II)/KPS process was drastically decreased in the various water matrices.