TiO_2光催化对微滤去除腐殖酸的膜污染控制研究

着重研究了不同紫外灯光源和照射时间条件下,TiO_2光催化(PCO)对微滤去除腐殖酸过程中的膜污染控制,并探讨了膜污染的控制机理。研究结果表明,TiO_2光催化能有效提高微滤对腐殖酸的去除,同时降低膜通量的下降,起到有效控制膜污染的作用。进一步的实验分析表明,TiO_2光催化控制膜污染的主要机理在于将腐殖酸降解为易于被TiO_2吸附的小分子量物质,吸附腐殖酸降解产物后的TiO_2聚合颗粒粒径增大,易于在膜表面形成更为松散的沉积层,并使膜污染从以膜孔堵塞和沉积层污染为主转化为以沉积层污染为主的可逆性污染。

Effect of TiO2 photocatalytic oxidation on control of membrane fouling by humic acid in microfiltration

The effect of the UV light source and its irradiation time on the removal of humic acid and the flux of microfiltration (MF), and the fouling control mechanism by TiO_2 photocatalytic oxidation ( PCO) were given. Results showed that TiO_2 photocatalytic oxidation was able to improve the removal of humic acid and slow down the flux reduction, at the same time played a role in membrane fouling control. The fouling control mechanism was proposed. Humic acid was first degraded into smaller molecular weight ones, which were easily to be adsorbed by TiO_2 to form larger aggregated particles. These larger aggregated particles were then deposited on the membrane surface loosely but without blocking the membrane pores,which transferred the fouling from the irreversible phase (pore blocking) to reversible phase (cake layer).