Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Mumbai, 400 076, India.
Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Mumbai, 400 076, India.
Environ Res. 2021 Sep;200:111515. doi: 10.1016/j.envres.2021.111515. Epub 2021 Jun 12.
The presence of pharmaceutically active compounds in aquatic bodies is a global concern, and suitable treatment technologies are required. In this study, the efficacy of photocatalytic, sonocatalytic, and sonophotocatalytic oxidation processes for the degradation of amoxicillin (AMX) was investigated using visible light with N doped TiO (N-TiO) nanoparticles as the catalyst and low-frequency ultrasound in a novel multifrequency reactor. The influence of different operational parameters on the extent of AMX degradation was studied. Sonophotocatalytic oxidation was found more efficient for AMX degradation when compared to photocatalysis or sonocatalysis alone, and may be due to the reduced bandgap of the catalyst, enhanced cavitation effect due to the presence of the solid catalyst, and improved mass transfer of pollutants. AMX degradation during sono, photo, and sonophotocatalytic oxidation processes was in good agreement with pseudo-first-order kinetics. Empirical kinetic models were also developed using multiple linear regression for predicting the degradation efficiency accounting for the operational parameters. Scavenger experiments suggested that OH radicals largely contributed to AMX degradation, and a plausible mechanism for degradation was proposed. Further, possible degradation pathways for all three treatment processes are also proposed after identifying the degradation products.
水体中药物活性化合物的存在是一个全球性的问题，需要合适的处理技术。在这项研究中，使用可见光和 N 掺杂 TiO（N-TiO）纳米粒子作为催化剂，在新型多频反应器中采用低频超声，研究了光催化、声催化和超声光催化氧化工艺对阿莫西林（AMX）降解的效果。研究了不同操作参数对 AMX 降解程度的影响。与单独的光催化或声催化相比，超声光催化氧化对 AMX 降解更有效，这可能是由于催化剂的带隙减小、由于固体催化剂的存在而增强的空化效应以及污染物的传质得到改善。在超声、光和超声光催化氧化过程中，AMX 的降解符合准一级动力学。还使用多元线性回归开发了经验动力学模型，用于预测考虑操作参数的降解效率。清除实验表明，OH 自由基对 AMX 的降解贡献很大，并提出了一种可能的降解机制。此外，在确定降解产物后，还提出了所有三种处理过程的可能降解途径。
