Kinetic modeling of degradation for alizarin yellow R by the activated persulfate by Fe⁰ (ZVI) under UV light

Abstract

Advanced oxidation processes (AOPs) based on persulfate activated by zero valent iron (ZVI) were used to remove azo dyes in water. Activated persulfate generate to strong free radicals SO4‐• (E0 = 2.6 V) and HO• (E0 = 2.8 V). The UV light was used to improve the efficiency of this activated persulfate. This study focused on determining a kinetic model, reaction rate constants and concentrations of SO4‐• and HO• in processes of persulfate activated by ZVI with or without UV light to degrade alizarin yellow R (AY). By using both experimental resultsand data analysis using the developed pseudo‐first‐order kinetic model, the reaction rate constants for the reaction of AY at pH 4.5 were determined to be 6.98 × 10‐4 s‐1 and 1.38 × 10‐3 s‐1 in condition without UV light and with UV light, respectively. The concentrations of SO4‐•, HO• at 30 minutes of the process were 9.41 × 10‐4 mM, 4.12 × 10‐7 mM without UV and 8.58 × 10‐4 mM, 8.10 × 10‐7 mM with UV, respectively.