Fu Jian-feng, Ji Min, An Ding-nian
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
J Environ Sci (China). 2005;17(6):942-5.
The degradation of fulvic acid (FA) by nanoparticle TiO2 in a submerged membrane photocatalysis (SMPC) reactor was studied. In this reactor, photocatalytic oxidation and membrane separation co-occured. The continuous air supplier provided O2 for the photocatalytical reaction and mixed the solution through an airflow controller. The particle TiO2 could automatically settle due to gravity without particle agglomeration so it could be easily separated by microfiltration (MF) membrane. It was efficient to maintain high flux of membranes. The effects of operational parameters on the photocatalytic oxidation rate of FA were investigated. Results indicated that photocatalyst at 0.5 g/L and airflow at 0.06 m3/h were the optimum condition for the removal of fulvic acid, the removal efficiency was higher in acid media than that in alkaline media. The effects of different filtration duration on permeate flux rate of MF with P25 powder and with nanoparticle TiO2 were compared. Experimental results indicated that the permeate flux rate of MF was improved and the membrane fouling phenomenon was reduced with the addition of nanoparticle TiO2 catalyst compared with conventional P25 powder. Therefore, this submerged membrane photocatalysis reactor can faciliate potential application of photocatalytic oxidation process in drinking water treatment.
研究了在浸没式膜光催化（SMPC）反应器中纳米颗粒TiO₂对富里酸（FA）的降解情况。在该反应器中，光催化氧化和膜分离同时发生。连续空气供应器为光催化反应提供O₂，并通过气流控制器使溶液混合。颗粒状TiO₂可因重力自动沉降，不会发生颗粒团聚，因此可通过微滤（MF）膜轻松分离。维持膜的高通量效率很高。研究了操作参数对FA光催化氧化速率的影响。结果表明，0.5 g/L的光催化剂和0.06 m³/h的气流是去除富里酸的最佳条件，酸性介质中的去除效率高于碱性介质。比较了不同过滤时间对含P25粉末和含纳米颗粒TiO₂的MF渗透通量率的影响。实验结果表明，与传统的P25粉末相比，添加纳米颗粒TiO₂催化剂可提高MF的渗透通量率，并减少膜污染现象。因此，这种浸没式膜光催化反应器可促进光催化氧化工艺在饮用水处理中的潜在应用。
