TITLE:
Ultraviolet Light (UV)-Induced Photocatalytic Degradation of Diclofenac Using Naturally Derived TiO2@rGO Composite
AUTHORS:
Lorenz E. Borromeo, Lea P. Bongat, John Patrick S. Nuñez, Kirby F. Mendioro, Jocelyn R. Balisnomo
KEYWORDS:
Diclofenac, Photocatalysis, Optimization, Titania, Wastewater
JOURNAL NAME:
Open Access Library Journal,
Vol.10 No.4,
April
28,
2023
ABSTRACT: Diclofenac (DCF) is a non-steroidal anti-inflammatory drug (NSAID) used to relieve pain in joint-related diseases. It is not completely metabolized after consumption and cannot be easily removed using conventional wastewater treatment. DCF has been detected in water bodies and may pose chronic effects on the endocrines of living organisms even at low-level exposure. Heterogeneous photocatalysis provides an alternative and efficient method of degrading DCF. In this study, the photocatalytic removal of DCF was investigated using the synthesized TiO2@rGO composite. Reduced graphene oxide (rGO) was prepared from graphite powder by modified Hummer’s method using Capsicum annuum extract. Titanium dioxide (TiO2) was then impregnated in rGO via impregnation method. Adsorption and photocatalytic degradation experiments were conducted at room temperature using 100 mL of 10 mg·L-1 DCF solution. The effects of pH, catalyst loading, and UV irradiation time on the removal of DCF were assessed. Results of the parametric study showed that photocatalytic efficiency of TiO2@rGO composite in DCF degradation was directly proportional to the UV irradiation time and catalyst loading. The maximum DCF removal efficiency of 92.75% and nearly 100% was noted at 50 mg catalyst and 120 min irradiation time, respectively. Meanwhile, the maximum removal efficiency of 90.98% was noted at pH value of 6. Using response surface modelling, the optimum operating conditions in terms of maximum percent removal efficiency of DCF were pH at 6.44, irradiation time of 58.13 min, catalyst dosage of 49.98 mg, with 90% removal.