Improving degradation of paracetamol by integrating gamma radiation and Fenton processes

ABSTRACT

Degradation of paracetamol (N-(4-hydroxiphenyl)acetamide) in aqueous solution by gamma radiation, gamma radiation/H₂O₂ and gamma radiation/Fenton processes was studied. Parameters affecting the radiolysis of paracetamol such as radiation dose, initial concentration of pollutant, pH and initial oxidant concentration were investigated. Gamma radiation was performed using a ⁶⁰Co source irradiator. Paracetamol degradation and mineralization increased with increasing absorbed radiation dose, but decreased with increasing initial concentration of the drug in aqueous solution. The addition of H₂O₂ resulted in an increased effect on irradiation-driven paracetamol degradation in comparison with the performance of the irradiation-driven process alone: paracetamol removal increased from 48.9% in the absence of H₂O₂ to 95.2% for H₂O₂ concentration of 41.7 mmol/L. However, the best results were obtained with gamma radiation/Fenton process with 100% of the drug removal at 5 kGy, for optimal H₂O₂ and Fe²⁺ concentrations at 13.9 and 2.3 mmol/L, respectively, with a high mineralization of 63.7%. These results suggest gamma radiation/H₂O₂ and gamma radiation/Fenton processes as promising methods for paracetamol degradation in polluted wastewaters.

KEYWORDS:

• Advanced oxidation processes
• Fenton reaction
• gamma radiation
• paracetamol
• process intensification

Funding

This research was supported by the project TATARCOP of Instituto Superior de Tecnologías y Ciencias Aplicadas (InSTEC), Cuba.