Investigations on the degradation of an antibiotic Cephalexin using suspended and supported TiO2: Mineralization and durability studies

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• 作者：Palak Bansal ; Anoop Verma ; Kashish Aggarwal ; Amanjit Singh and Saurabh Gupta
• 刊名：The Canadian Journal of Chemical Engineering
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：94
• 期：7
• 页码：1269-1276
• 全文大小：5836K
• ISSN：1939-019X

文摘

Rising levels of antibiotics in treated wastewater pose a great threat to human health worldwide. The present study shows degradation studies of antibiotic Cephalexin using slurry and innovative fixed-bed photocatalysis under UVA (365 nm) irradiations. A UV-spectrophotometer/HPLC was used for analyzing the decay of Cephalexin. Studies showed that variation in UV intensity, dose variation of TiO₂ and H₂O_2, area by volume (A/V), and pH affect the degradation to a great extent. The degradation rate followed pseudo-first order kinetics with optimized conditions for degrading the antibiotic being TiO₂ 1.0 g · L⁻¹, H₂O₂ 0.15 mL, with UV intensity of 25 W · m⁻². The COD decrease (80 %) with the generation of nitrite, nitrate, and sulphate ions confirmed the mineralization of the selected compound. TiO₂-coated spherical cement beads were used for fixed-bed studies, which eliminates the implications of slurry mode photocatalysis. The beads were recycled for at least 50 cycles, which confirmed the durability of the catalyst, and characterized by SEM-EDAX. Attempts were made to study the pilot-scale fixed-bed baffled solar reactor for degrading Cephalexin, which confirmed 70 % degradation after 10 h.