Photo-catalytic Ozonation for Degrading TerephthalicAcid in Aqueous Environment

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 MnFe2 O4 /Willemite photo-catalyst.

In this research, the nanoparticles of MnFe2 O4 and Willemite were synthesized by co-precipitation reactions and wet mixing method, respectively. Then MnFe2 O4 / Willemite was synthesized by the immobilization of MnFe2 O4 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.

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.

Comparing experiments results in different processes, such as UV, UV-Cat, O3 , UVO3 , Cat-O3 , and UV-Cat-O3 revealed that photo-catalytic ozonation (O3 /MnFe2 O4 /Willemite) in the presence of UV for degradation of TPA in an aqueous environment, present the higher efficiency.