膜污染层是一种典型的多孔介质。在膜污染研究中,通常利用海藻酸钠为代表的多糖类污染液进行过滤实验。本文在海藻酸钠污染液中加入了酵母粉代表的蛋白质类污染物,对混合污染液进行了过滤实验。采用免疫荧光染色的方法对膜污染层内的多糖和蛋白质进行了标记,并利用共聚焦激光扫描显微镜进行观测。通过图像分割技术得到膜污染层孔隙和骨架的二值图,进而计算了多孔介质层的孔隙率。结果表明膜污染层孔隙率的减小与膜过滤过程中透膜流量的衰减相对应,蛋白质类污染物在过滤过程中限制了多糖类污染物在膜表面的附着与堆积。
Membrane fouling layer is a typical porous medium.Sodium alginate is widely used as a kind of polysaccharide pollutant in membrane fouling research.In this paper,a polysaccharide-protein mixed liquor was made for filtration tests.Polysaccharide and protein pollutants in fouling layer were labelled by fluorescent staining method and then fluorescent images were obtained using confocal laser scanning microscope(CLSM).The matrix volume and effective pore volume of fouling layer were retrieved from fluorescent images,and then the porosity was calculated The porosity decrease of fouling layer corresponded well with the flux attenuation of filtration membrane.And the protein component in the mixed liquor inhibited the accumulation of the polysaccharide component during the whole filtration process.