磁性复合材料活化过硫酸盐去除水中双酚A

Removing bisphenol A with magnetic sandwich composite activated peroxymonosulfate

将Fe_(3)O_(4)负载于具有二维层状结构的MXene,形成磁性三明治复合材料Fe_(3)O_(4)@MXene,活化过硫酸盐(PMS)去除水中的双酚A(BPA).探讨了PMS投加量、Fe_(3)O_(4)@MXene投加量、溶液初始pH值、BPA初始溶液浓度对BPA降解的影响.结果表明,BPA的降解符合准一级反应动力学.在25℃,BPA浓度25mg/L,Fe_(3)O_(4)@MXene投加量0.3g/L,PMS投加量3.3mmol/L,pH=6.0的条件下,反应90min后,BPA的降解率达97.4%.自由基淬灭实验及EPR实验证实,羟基自由基和硫酸根自由基是降解BPA的主导活性氧物种,此外单线氧也参与了降解.经由MXene负载的Fe_(3)O_(4)颗粒大小分布均匀,活性及稳定性均显著提高,MXene表面的Ti原子加速了Fe(II)/Fe(III)循环,从而加速了PMS活化.因此,Fe_(3)O_(4)@MXene可作为理想的过硫酸盐高级氧化过程的非均相催化剂.

The magnetic sandwich composite Fe_(3)O_(4)@MXene was prepared to activate peroxymonosulfate(PMS)for removing Bisphenol A(BPA)from water.The effects of PMS dosage,Fe_(3)O_(4)@MXene dosage,initial solution pH value and initial BPA concentration on BPA degradation were investigated.The results show that the degradation of BPA conformed to the quasi-first order reaction kinetics.At 25℃,the combination of Fe_(3)O_(4)@MXene dosage of 0.3g/L,PMS dosage of 1.01g/L and initial pH of 6.0could degrade 97.4%of BPA(25mg/L)after 90-minute,in which hydroxyl radical and sulfate radical were the dominant reactive oxygen species for BPA degradation despite having singlet oxygen involved.The MXene-supported Fe_(3)O_(4)particles showed a uniform size distribution with obviously improved activity and stability.The Ti atoms on the surface of MXene helped accelerate the Fe(II)/Fe(III)redox cycle,which thus improved PMS activation.Evidently,the Fe_(3)O_(4)@MXene can be used as an ideal heterogeneous catalyst for the advanced oxidation process of persulfate.