چكيده لاتين :
Pharmaceutical waste disposal procedure involves a number of traditional techniques, such as sewer
and incineration [1]. Despite the widespread utilization of these techniques, they do not help to remove
drugs from contaminated waters. Waste drugs are flowed into water through wastewaters or direct
disposal of pharmaceutical producers. Therefore, strategies should be adopted to prevent disposing
waste drugs into environment before suitable treatment [2,3]. Phenazopyridine (PhP), phenyldiazenyl
pyridine-2, 6-diamine, exerts an analgesic effect on the mucosa of the urinary tract and is used to
provide symptomatic relief of pain in conditions such as cystitis and urethritis. In this paper, removal
efficiency of PhP as a model pharmaceutical contaminant was tested in a batch-recirculated
photoreactor packed with immobilized TiO2-P25 nanoparticles on glass beads. Influence of different
operational parameters such as irradiation time, initial concentration of PhP, volume of solution,
volumetric flow rate, pH and power of light source were investigated. Results indicated that removal
percent increases with the rise of irradiation time, volumetric flow rate and power of light source but
decreases with the rise of initial concentration of PhP and volume of solution. Highest removal percent
was obtained in the natural pH of PhP solution (pH = 5.9). Under optimal conditions complete PhP
degradation with initial concentration of 10 mg L-1 was obtained with 60 min irradiation time. The
packed bed photoreactor with TiO2-P25 coated onto glass beads can be a promising alternative for the
decomposition of recalcitrant organic pollutants such as PhP in wastewater.
