载钛羟基磷灰石对水中EE2光催化降解规律及途径研究

以 17α-乙炔雌二醇(EE2)为目标污染物, 以载钛羟基磷灰石(TiHAP)为催化剂, 对比研究TiHAP和TiO₂对EE2的光催化规律、影响因素及机理, 分析光催化降解的中间产物及降解途径。实验结果表明, TiHAP薄膜对EE2的降解速率高于TiO₂薄膜; 随着Fe³⁺浓度增加, TiHAP降解EE2的速率没有明显变化, TiO₂降解EE2的速率则先增加后减小; 随着富里酸(FA) 浓度的增加, TiHAP降解EE2的速率减小, 而TiO₂降解EE2的速率升高。用LC-MSⁿ对TiHAP光催化降解EE2过程中产生的中间产物进行分析, 在中性pH条件下共确定9种降解产物, 比同样pH值下以TiO₂为催化剂检出的产物种类多, 推断其降解的主要途径是苯环羟基化、开环羧基化以及脱羧等一系列反应。

Photocatalytic Degradation and Reaction Pathway of EE2 in Aqueous Solution by TiHAP

Selecting 17α-ethynylestradiol (EE2) as the target pollutant and TiHAP as the catalyst, comparative studies of the photocatalytic degradation of TiHAP and TiO₂ were conducted, and the influencing factors and intermediate products were also investigated. The results show that the EE2 degradation rate by TiHAP film was faster than that by TiO₂ film. The EE2 degradation rate of TiHAP remained the same with the increase of Fe³⁺ concentration, but decreased with the increase of FA concentration. For TiO₂, the EE2 degradation rate initially increased and then decreased with increasing Fe³⁺ concentration, and increased with increasing FA concentration. The photocatalitic degradation intermediates of EE2 by TiHAP were identified by LC-MSⁿ. The results show that nine kinds of intermediates were identified. Compared with TiO₂, more kinds of intermediates were identified for EE2 photocatalytic degradation by TiHAP. Transformation of the phenolic moiety, hydroxylation, ring opening and carboxylation, and carboxylation were the primary reaction pathways.