Degradation mechanisms of cefotaxime using biochar supported Co/Fe bimetallic nanoparticles

作者：Wu, Hongwei^*; Feng, Qiyan^*; Lu, Ping; Chen, Meng; Yang, Hong

来源：Environmental Science: Water Research and Technology , 2018, 4(7): 964-975.

DOI：10.1039/c8ew00163d

• ZERO-VALENT IRON
• WASTE-WATER TREATMENT
• AQUEOUS-SOLUTION
• FE/NI NANOPARTICLES
• ZEROVALENT IRON
• PD/FE CATALYST
• REMOVAL
• DECHLORINATION
• ANTIBIOTICS
• KINETICS

Ecological risks caused by residual antibiotics have increasingly attracted great attention. In this study, a highly efficient novel adsorbent based on Co/Fe bimetallic nanoparticles loaded with alkali modified biochar (Co/Fe/MB) was prepared to remove cefotaxime from an aqueous solution. The prepared composites were characterized with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of Co loading, adsorbent dosage, initial solution pH and anions (Cl-, HCO3- and EDTA) on the removal of cefotaxime were investigated. Due to the synergetic reaction of the adsorption and reduction mechanism, Co/Fe/MB revealed the highest cefotaxime removal efficiency (99.23%) in 100 min at the condition of pH = 5, T = 298 K, Co/Fe/MB dosage = 0.8 g L-1, Co loading = 0.4 wt%, cefotaxime = 20 mg L-1. The removal efficiency was further enhanced in the presence of EDTA and Cl- because of the destruction of a passivation layer on iron surface. Additionally, the degradation products and possible degradation pathway of cefotaxime by Co/Fe/MB were analyzed by high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS). The spectra revealed that the opening and cleavage of the -lactam ring was the first step for cefotaxime degradation. The Co/Fe/MB composite was found to be an efficient material to remove cefotaxime from the solution.

• 出版日期2018-7
• 单位中国矿业大学（北京）; 枣庄学院