Investigation on the efficiency of a Packed Bed Reactor with immobilized TiO2-P25 nanoparticles on glass beads in the removal of Phenazopyridine

Heterogeneous photocatalysis is a promising method among advanced oxidation processes (AOPs) which is able to breakdown many organic pollutants. This domain is particularly oriented towards application and has a strong impact on design and construction of new photochemical reactors [1]. Since photocatalysis are often applied as suspension [2], hence, the separation of photocatalyst particles from its aqueous suspensions represents a serious problem for practical engineering. In this work, TiO2-P25 nanoparticles were immobilized on glass beads by heat attachment method [3]. Then glass beads were packed into an annular reactor. Efficiency of photoreactor has been evaluated in the removal of Phenazopyridine (PhP) as a refractory pollutant from petrochemical industry. Phenazopyridine is an important chemical widely used in the production of polyester fiber, non-fiber field, PET-film; poultry feed additives, dyes, medicines, pesticides and other chemical compounds [4]. Reactor comprises from an annular photoreactor packed with catalyst supported on glass beads and a continuous stirred tank reactor (CSTR) (Fig. 1). The radiation source in annular photoreactor was UV-C lamp. The solution was recirculated with a peristaltic pump (Heidolph, PD 5001) with a known flow rate into the PBR and regularly, the PhP concentration was analyzed at the CSTR with a UV-vis spectrophotometer at 430 nm. Results of experiments indicate this photoreactor can be used efficiently for removal of PhP from aqueous solution. Removal percent was a function of initial concentration of PhP, light intensity, volume of solution and volumetric flow rate of liquid. Results show that the light intensity plays an important role on the removal PhP in this system and increasing of PhP initial concentration and volume of solution causes a decrease in the removal of PhP.

Keywords:

Batch-recirculated photoreactor , TiO2-P25 nanoparticles , Phenazopyridine