Role of pH in the Aqueous Phase Reactivity of Zerovalent Iron Nanoparticles with Acid Orange 7, a Model Molecule of Azo Dyes

Figure 4

Section (a): UV-Vis spectra of 0.67 mM AO7 solution and of the supernatant solutions in contact with Fe_fresh at pH = 6.80 after 90 min (grey curve) and after 168 h (black curve). Section (b): trend in the intensity of the AO7 band at 484 nm as a function of time.

(a)

(b)