基于静电纺丝膜的Fenton法降解双氯芬酸钠

Degradation of diclofenac sodium by electrospinning fibers-based Fenton method

通过浸渍法将铁盐负载于静电纺丝纤维膜制备了类Fenton催化剂,并通过扫描电子显微镜(SEM)对静电纺丝膜进行了表征,研究了该催化剂降解双氯芬酸钠的特性及其重复利用率。结果表明,静电纺丝纤维膜反应前后膜结构良好,反应过程中铁离子几乎无溶出;膜对双氯芬酸钠有一定的吸附能力,去除率约为6.96%。当双氯芬酸钠初始浓度为20 mg·L-1,按0.310 g·(100 m L)-1比例加入催化剂时,H_2O_2最佳用量为340 mg·L-1。溶液的初始p H值对实验结果影响较大,酸性条件更利于双氯芬酸钠的降解,最佳p H值为3.14,但该催化剂所适用的p H值范围较之传统Fenton法有明显拓展。所制备的催化剂重复利用率高,循环使用4次后,催化活性无明显改变,4 h的去除率依然高达95%以上。反应中双氯芬酸钠主要生成乙酸等小分子化合物,最终可氧化为CO2和H2O。

A Fenton-like catalyst was synthesized by loading ferric salt onto electrospinning fibers, and characterized with a scanning electron microscope （SEM）. The degradation of diclofenac sodium （DS） by the synthesized catalyst was studied, along with the catalyst recycle rate. The results indicated that the fibers were well-formed before and after the reaction, and that nearly no iron ion was released into the solution. The adsorp- tion of DS by the catalyst was approximately 6.69%. When the initial concentration of DS was 20 mg · L-1 , and the dosage of catalysts was 0. 310 g · （ 100 mL） -1, the optimal dosage of H202 was 340 mg· L-1 The effect of the initial pH value was significant, and acidic conditions were beneficial for the degradation of DS. In this stud- y, the optimal pH value was 3. 14; however, the applicable range of pH of the synthesized catalyst was broader than that of the traditional Fenton catalyst. The recycle rate of the catalyst was high, and the removal rate excee- ded 95% for a catalyst used four times after reacting for 4 h. DS was primarily transformed into small molecules, such as acetic acid, and could eventually be oxidized into CO2 and H2O.