Gamma and UV radiation induced degradation of methotrexate (anti-rheumatic drug) in aqueous solution and conditions optimization
Muhammad Imran Kanjal, Majid Muneer, Ijaz Ahmad Bhatti, Muhammad Saeed, Atta ul Haq, Nighat Zia Ud Den, Ehsan ul Haq, Jan Nisar, Munawar Iqbal
Abstract
ABSTRACT Ionizing radiation-induced degradation of methotrexate (MTX) was carried out by UV and gamma-ray in combination with H 2 O 2 (0.5 mL/L) as a function dose. The γ radiation dose, UV irradiation time, H 2 O 2 dose and initial concentration of MTX were optimized and efficiency was evaluated based on degradation and chemical oxygen demand (COD) removal. The MTX removal efficiency (G-value), dose constant (k), D 0.5 , D 0.9 , and D 0.99 were calculated for γ-ray treatment. The MTX degradation was 78.17% and 86.62% when treatment was performed with 90 min UV exposure alone and in the presence of H 2 O 2 (oxidant), whereas γ and γ/H 2 O 2 furnished up to 93.66% and 99% degradation of MTX for the absorbed dose of 4 kGy. The COD reduction was 65% and 80% for UV/H 2 O 2 and gamma/H 2 O 2 , respectively. The MTX degradation progress was monitored by high-performance liquid chromatography, Fourier-transform infrared spectroscopy and gas chromatography-mass spectrometry and results revealed that MTX was degraded efficiently by UV and γ radiation. The treatment could be used for the degradation of wastewater containing anti-rheumatic drugs.