Photo-catalytic Ozonation for Degrading Terephthalic Acid in Aqueous Environment

Background & Aims of the Study: Terfetalic Acid (TPA ) is produced in large quantities and used in various industries. Besides, TPA is among the main sources of water pollution in industrialized countries. TPA photo-degradation process was performed in a Circulating Fluidized Bed Reactor (CFBR) by one Ultraviolet type A (UV-A) lamp and ozone generator with MnFe2O4/Willemite photo-catalyst. Materials and Methods: In this research, the nanoparticles of MnFe2O4 and Willemite were synthesized by co-precipitation reactions and wet mixing method, respectively. Then MnFe2O4/ Willemite was synthesized by the immobilization of MnFe2O4 on Willemite by mechanical method. Full factorial experimental design with 4 factors, including the pH, the initial concentration of TPA, the amount of Catalyst (Cat.), and O3 dosage was used for modeling and optimizing the process. Results: In the optimal conditions, the amounts of pH, TPA, Cat., and O3 were obtained equal to 9, 20 ppm, 1.5 g/L, and 2.17 mg/h, respectively. In these conditions, degradation efficiency was obtained to be 98.2695%, and decomposition kinetics was determined as pseudo-first-order with Kapp=0.2707 min-1, kLH=3.729 ppm min-1, and kadd=0.051 ppm-1. Conclusion: Comparing experiments results in different processes, such as UV, UV-Cat, O3, UVO 3, Cat-O3, and UV-Cat-O3 revealed that photo-catalytic ozonation (O3/MnFe2O4/Willemite) in the presence of UV for degradation of TPA in an aqueous environment, present the higher efficiency.