GO-TiO2改性PVDF复合膜去除微污染水体中氨氮

以氧化石墨烯（GO）、二氧化钛（TiO₂）和氧化石墨烯-二氧化钛（GO-TiO₂）为改性物质，借助真空过滤法对聚偏氟乙烯（PVDF）微滤膜进行改性制备复合膜.利用接触角测量仪、扫描电子显微镜、傅里叶红外变换光谱、X射线粉末衍射仪等手段探究了复合膜的结构和亲水性.同时选用腐殖酸（HA）作为水中微污染物的代表考察了复合膜的抗污染性能.选择常州滆湖支浜水样作为原水，研究了复合膜在黑暗及紫外光条件下对氨氮的去除效果.结果表明，GO、TiO₂和GO-TiO₂（GT）复合膜均具有优于PVDF膜的亲水性和抗污染性能，黑暗条件下，GO浓度为1mg/mL的GO复合膜氨氮去除率最高，达到26.4%；紫外光条件下，GO和TiO₂间存在协同作用，GO-TiO₂浓度为1mg/mL、GO/TiO₂=3：1的GT复合膜氨氮去除效率达到最佳（58.2%）.

Removal of ammonia nitrogen from micro-polluted water by GO-TiO2 modified PVDF composite membrane

The polyvinylidene fluoride (PVDF) microfiltration membrane was modified by vacuum filtration method with graphene oxide (GO), titanium dioxide (TiO₂) and graphene oxide-titanium dioxide (GO-TiO₂) as modifiers. The structure and hydrophilicity of the composite membranes were investigated by contact angle measurement, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). At the same time, humic acid (HA) was selected as the representative of micro-pollutants in water to examine the anti-pollution performance of the composite membrane. The removal efficiencies of ammonia nitrogen by composite membrane under dark and ultraviolet light conditions were studied by using the lake water samples from Gehu Lake branch in Changzhou as raw water. The results showed that GO, TiO₂ and GO-TiO₂ (GT) composite membranes had better hydrophilicity and anti-pollution performance than PVDF membranes. Under dark condition, GO composite membrane with GO concentration of 1mg/ml had the highest ammonia nitrogen removal rate (26.4%) under dark condition, while that of GT composite membrane with GO-TiO₂ concentration of 1mg/mL and GO/TiO₂=3:1could reach the best (58.2%), for there was synergistic effect between GO and titanium dioxide under ultraviolet light.