氧化锌光催化/超滤膜组合工艺对水中富里酸的去除

Removal of Fulvic Acid by Combination of ZnO Photocatalytic and Ultrafiltration Membrane

以富里酸(FA)为模拟废水,探究了ZnO投量、溶液初始pH值、曝气量等因素对自制氧化锌光催化过程去除效能的影响,考察了光催化/超滤膜组合工艺对FA的去除效果以及过滤不同光催化氧化时间的FA溶液时膜通量的变化,并利用扫描电镜(SEM)分析了由FA引起的不可逆膜污染。结果表明,光催化氧化反应最佳条件如下:Zn O投加量为0.3 g/L、FA溶液初始p H值为7、曝气量为1.2 L/min,在此条件下光催化反应150 min后,对UV_(254)及TOC的去除率分别可达到92.6%和56.2%。超滤膜组合工艺不仅可以实现催化剂与处理水的有效分离,且随着光催化时间的增加,膜通量衰减速度下降,有效减缓了FA溶液造成的不可逆膜污染。

With fulvic acid （FA） as simulated wastewater, the influence of different conditions on pollutant removal rate in the zinc oxide （ZnO） photocatalytic stage was studied. During the photocatalyticultrafihration membrane combination proeess, the removal of FA and membrane flux change caused by FA solution with different photocatalytic oxidation time were investigated. Scanning electron microscope （SEM） was used to analyze irreversible membrane fouling caused by FA. The results showed that the op- timal conditions of photocatalytic reaction were 0.3 g/L of ZnO dosage, the neutral initial pH and l. 2 L/ rain of aeration rate. Under the eondition, the UV254 and TOC removal rates reached 92.6% and 56.2% after 150 min photocatalysis respectively. The combination process with ultrafiltration membrane could not only effectively separate the catalyst from treated water, but also deereased the decay rate of membrane flux with the increase of photocatalytie time, whieh could effectively reduce the irreversible membrane fouling caused by FA solution;