Co-Cu双金属氧化物活化过一硫酸盐去除水中磺胺甲噁唑

Enhanced removal of sulfamethoxazole via peroxymonosulfate activated by the Co-Cu bimetallic oxide

采用钴铜双金属氧化物(Co-Cu)为催化剂,活化过一硫酸盐(PMS)降解水中的磺胺甲噁唑(SMX).使用场发射扫描电镜(FESEM)、透射电镜(TEM)、X射线光电子能谱(XPS)、X射线衍射(XRD)对催化剂的形貌和元素组成进行表征.考察了催化剂和PMS浓度、无机阴离子和富里酸(FA)对Co-Cu/PMS体系降解SMX的影响.结果表明,当pH为7.0时,在催化剂用量为50 mg·L^(-1),PMS浓度为0.5 mmol·L^(-1)条件下,50 mg·L^(-1)的SMX在30 min内去除率为95.6%,增加PMS浓度或提高催化剂用量均可加快SMX的降解速率.水中FA与HCO3-对SMX的去除率有一定的抑制作用,而Cl^(-)和SO_(4)^(2-)对反应无影响.淬灭实验与电子顺磁共振(EPR)结果显示,硫酸根自由基(SO_(4)^(·-))和单线态氧(^(1)O_(2))为Co-Cu/PMS体系中主要的活性氧物种(ROS).XPS分峰结果表明,在钴铜双反应活性中心中Cu^(+)/Cu^(2+)循环是活化PMS的主要成分.

Co-Cu bimetallic oxide was used as a catalyst for the activation of peroxymonosulfate(PMS)to degrade sulfamethoxazole(SMX)in water.The morphology and elemental composition of the as-prepared catalyst were characterized by field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),and X-ray diffraction(XRD).In the catalytic system,95.6%of SMX was removed within 30 min when the pH was 7.0,the catalyst dosage was 50 mg·L^(-1),and the PMS concentration was 0.5 mmol·L^(-1).The removal of SMX was accelerated with increasing PMS concentration and catalyst dosage.FA and HCO3-had an inhibitory effect on the removal of SMX,while Cl^(-)and SO_(4)^(2-)exhibited no significant impact.Quenching experiments and electron paramagnetic resonance(EPR)results indicated that sulfate radicals(SO_(4)^(·-))and singlet oxygen(^(1)O_(2))were the main reactive oxygen species(ROS)in the Co-Cu/PMS system.The XPS peak results indicated that the Cu^(+)/Cu^(2+)cycle played an important role in the PMS activation of the Co-Cu.