Research Group of Water Pollution Control and Water Reclamation, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Research Group of Water Pollution Control and Water Reclamation, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Environ Pollut. 2020 Aug;263(Pt B):114436. doi: 10.1016/j.envpol.2020.114436. Epub 2020 Mar 30.
In this work, the electrochemical degradation of antibiotic ceftazidime has been studied using a novel rare earth metal Ce and carbon nanotubes codoped PbO electrode. A competitively high oxygen evolution potential (2.4 V) and enhanced catalytic surface area were obtained, evidence by LSV and CV electrochemical characterization. The G/CNT-Ce/PbO-Ce electrode possessed a more compact structure and a smaller grain size than the other PbO and Ce-PbO electrodes, exhibiting a prolonged service lifetime, evidence by accelerated lifespan test and recycling degradation experiment. As electrolysis time reached 120 min, the removal efficiency of ceftazidime and TOC arrived at 100.0% and 54.2% respectively in 0.05 M NaSO solution containing 50 mg⋅L ceftazidime. The effect of applied current density, pH value, initial ceftazidime concentration and chloride contents on the degradation performance were systematically evaluated. The results demonstrated that electrochemical oxidation of ceftazidime over the G/CNT-Ce/PbO-Ce electrode was highly effective, and the mineralization rate was greatly improved, compared with pristine PbO electrode. Considering the toxicity was increased after 30 min electrolysis, the intermediates were quantitatively investigated through HPLC-MS, GC-MS and IC technology. According to the identified products, a reaction mechanism has been proposed and pyridine and aminothiazole were detected with concentration from approximately 1 to 3 mg⋅L, which were regarded as toxic byproducts during electrooxidation. Further electrocatalyzing by ring cleavage reaction and complete mineralization to CO, NO and NH was proposed, which demonstrated the G/CNT-Ce/PbO-Ce electrode exhibited high efficiency for ceftazidime removal in mild conditions.
在这项工作中，使用新型稀土金属 Ce 和碳纳米管共掺杂 PbO 电极研究了抗生素头孢他啶的电化学降解。通过 LSV 和 CV 电化学特性研究，得到了竞争高的氧气析出电位（2.4 V）和增强的催化表面积。G/CNT-Ce/PbO-Ce 电极比其他 PbO 和 Ce-PbO 电极具有更紧凑的结构和更小的晶粒尺寸，通过加速寿命测试和回收降解实验证明具有更长的使用寿命。随着电解时间达到 120 分钟，在 0.05 M 的 NaSO 溶液中含有 50 mg⋅L 的头孢他啶时，头孢他啶和 TOC 的去除效率分别达到 100.0%和 54.2%。系统评估了施加电流密度、pH 值、初始头孢他啶浓度和氯含量对降解性能的影响。结果表明，与原始 PbO 电极相比，G/CNT-Ce/PbO-Ce 电极上的电化学氧化对头孢他啶具有高效的降解性能，并且大大提高了矿化率。考虑到 30 分钟电解后毒性增加，通过 HPLC-MS、GC-MS 和 IC 技术对中间产物进行了定量研究。根据鉴定的产物，提出了一种反应机制，并检测到浓度约为 1 至 3 mg⋅L 的吡啶和氨基噻唑，它们被认为是电氧化过程中的有毒副产物。进一步通过环裂解反应和完全矿化到 CO、NO 和 NH 进行电催化，表明 G/CNT-Ce/PbO-Ce 电极在温和条件下对头孢他啶的去除具有高效性。
