Co/Fe₃O₄@Zeolite磁性催化剂的结构和活化降解盐酸四环素性能

Structure and Activation Performance of Co/Fe₃O₄@Zeolite Magnetic Catalyst for Degradation of Tetracycline Hydrochloride

摘要: 本研究采用高能球磨法制备了钴掺杂磁性沸石(Co/Fe₃O₄@Zeolite)磁性催化剂，并将其用于活化过一硫酸盐(PMS)降解盐酸四环素(TCH)。利用XRD、VSM、SEM和EDS等表征对Co/Fe₃O₄@Zeolite复合催化剂的形貌和结构进行测试，结果表明Co/Fe₃O₄均匀地包覆在Zeolite的表面，并且催化剂具有较好的磁性可通过磁铁进行有效的磁分离便于循环利用。通过进行不同的反应体系对比，不同PMS用量、催化剂用量、pH值、循环实验、共存阴离子实验和自由基猝灭实验来评估Co/Fe₃O₄@Zeolite复合催化剂的催化性能。结果表明，在催化剂添加量为0.40 g/L、PMS添加量为2.0 mmol/L、pH为7时，催化剂的催化效果最好，50 mg/L的TCH去除率可达到98.8%。溶液中共存的阴离子如$C{O}_3^{2-}$ 、$S{O}_4^{2-}$ 、Cl⁻和$HP{O}_4^{2-}$ 对催化剂的影响较小。经过5次循环实验，TCH的降解率仍能保持在80%以上，表明催化剂具有良好的循环稳定性。自由基猝灭实验表明¹O₂、$O_2^{·-}$ 和$S{O}_4^{·-}$ 在TCH的降解过程中起主导作用。

Abstract: In this study, cobalt doped magnetic zeolite (Co/Fe₃O₄@Zeolite) magnetic catalyst was prepared by high energy ball milling and used to activate peroxymonosulfate (PMS) to degrade tetracycline hydrochloride (TCH). The morphology and structure of Co/Fe₃O₄@Zeolite composite catalyst were tested by XRD, VSM, SEM and EDS. The results showed that Co/Fe₃O₄ was uniformly coated on the surface of Zeolite. Moreover, the catalyst has good magnetic properties and can be effectively separated by magnets to facilitate recycling. The catalytic performance of Co/Fe₃O₄@Zeolite composite catalyst was evaluated by comparing different reaction systems, different PMS dosage, catalyst dosage, pH value, cycling experiment, coexistence anion experiment and free radical quenching experiment. The results showed that when the addition of catalyst was 0.40 g/L, the addition of PMS was 2.0 mmol/L and pH was 7, the catalytic effect was the best, and the TCH removal rate of 50 mg/L could reach 98.8%. The co-existing anions such as $C{O}_3^{2-}$ , $S{O}_4^{2-}$ , Cl⁻ and $HP{O}_4^{2-}$ in the solution have little effect on the catalyst. After 5 cycles of experiments, the degradation rate of TCH can still remain above 80%, indicating that the catalyst has good cyclic stability. Radical quenching experiments show that ¹O₂, $O_2^{·-}$ and $S{O}_4^{·-}$ play a leading role in the degradation of TCH.