利用溶胶-凝胶法制备磁载光催化剂Ti O2/Si O2/γ-Fe2O3。采用X-射线衍射(XRD)、扫描电镜(SEM)和比表面积(BET)对其晶型、表面形貌和多孔性进行分析,通过振动样品磁强计(VSM)测量磁性,应用高效液相色谱检测内分泌干扰物双酚A(BPA),探讨水中p H值和催化剂浓度对磁载光催化剂Ti O2/Si O2/γ-Fe2O3催化降解BPA的影响。结果表明,BPA的光催化降解曲线很好地符合一级反应动力学方程,反应速率常数主要与催化剂表面上电荷和中间产物的聚集,以及紫外光的利用率有关。光照120 min后,BPA降解基本完成,剩余浓度基本达到稳定。较低的p H值有利于BPA的去除;随着催化剂浓度增大,BPA去除率呈现先上升后下降的趋势。在BPA初始浓度为300μg/L,紫外光强为434μW/cm2,p H=5,催化剂浓度为4g/L时,BPA的去除率达到最大值66.62%。
The magnetic photocatalyst was prepared by sol-gel method,the crystal type,morphology and structure of magnetic photocatalyst were characterized by X-ray diffraction( XRD),scanning electron microscopy( SEM)and Brunauer-Emmett-Teller equation( BET),the magnetism was detected by vibrating sample magnetometer,the concentrations of BPA over photocatalytic degradation were monitored with HPLC. The influences of p H and photocatalyst dosage on the degradation rate were analyzed. The results showed that the first order reaction kinetics model could be used to simulate the degradation of BPA,the reaction rate parameters were strongly related to the accumulation of charge and the intermediate products,and the utilization of UV light on photocatalyst surface. The degradation processes were basically completed and remained concentration of BPA was basically stable in 120 min. Lower p H value was beneficial to the degradation of BPA; as the photocatalyst dosage increased,BPA removal rate showed a downward trend after the first rise. Under the conditions of initial BPA concentration 300. 0 μg / L,UV intensity 434 μW / cm2,p H = 5,photocatalyst dosage 4 g /L,the BPA degradation rate reached the maximum value of66. 62% after reacting for 120 min.