微波法制备磷酸化石墨烯@CoFe_(2)O_(4)及其对氟喹诺酮类抗生素的吸附

Synthesis of phosphorylated graphene@CoFe_(2)O_(4) by microwave method for the adsorption of fluoroquinolone antibiotics

本研究通过微波法制备了磷酸功能化磁性石墨烯(PG@CoFe_(2)O_(4))材料,并用其吸附水中6种氟喹诺酮类抗生素(FQs).采用扫描电镜、透射电镜、X射线衍射、磁滞回线等对复合材料进行系统的表征.系统考察了Cl^(-)、HCO_(3)^(-)/SO_(4)^(2-)和腐殖酸(HA)等对FQs吸附的影响.实验结果显示,在pH=4.0的情况下,PG@CoFe_(2)O_(4)投加量20.0 mg,30 min内6种目标物的去除率最高可达到95.5%.低浓度促进吸附而高浓度则抑制吸附,HCO_(3)^(-)/SO_(4)^(2-)和HA几乎不影响吸附过程,而Cr^(3+)和Cu^(2+)抑制FQs的吸附.准一级动力学模型和Freundlich模型拟合效果较好,说明吸附过程以化学吸附为主.两种实际水样中FQs的去除率均高达89.6%以上.实验表明,PG@CoFe_(2)O_(4)对含有氨基和卤素基团的污染物存在特异性吸附.

Phosphorylated magnetic graphene(PG@CoFe_(2)O_(4))were fabricated by microwave radiation method and used to adsorb six fluoroquinolone antibiotics(FQs)in water.The composites were systematically characterized by X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The effects of,Cl^(-)、HCO_(3)^(-)/SO_(4)^(2-),and humic acid(HA)on the adsorption of FQs were systematically investigated.The experimental results showed that the maximum removal efficiency of six targets could recah up to 95.5%within 30 min based on the condition of pH=4.0,PG@CoFe_(2)O_(4)20.0 mg.Also,low concentrations of promoted adsorption while high concentrations inhibited adsorption,HCO_(3)^(-)/SO_(4)^(2-),and HA hardly affected the adsorption process,while Cr^(3+)and Cu^(2+)inhibited the adsorption of FQs.Besides,the quasi-first-order kinetic model and Freundlich model fit well,indicating that the adsorption process is dominated by chemisorption.The removal efficiency of FQs in both actual water samples were above 89.6%.The experiments showed that the PG@CoFe_(2)O_(4)was specific for the adsorption of pollutants containing amino and halogen groups.