Abstract
A super-resolution microscopy, i.e. Stochastic Optical Reconstruction Microscopy (STORM), was applied as a new visualization method of internal membrane fouling. The purpose of this study was to evaluate the backwashing and chemical cleaning effectiveness on ultrafiltration membranes fouled with BSA by using Confocal Laser Scanning Microscopy(CLSM) and STORM. Comparing BSA-Alexa Fluor 647 conjugate with BSA which was labelled by Alexa Fluor 647 after chemical cleaning, the latter was not influenced by chemical cleaning and had a good emission in the analysis of CLSM and STORM. However, it would lead to false luminescent spots in STORM analysis if the rinse was not well done. In the analysis of CLSM, BSA fouled within the separation layer of membrane was quantified successfully, but a small quantity of BSA inside the membrane was not detected. On the other hand, in the analysis of STORM, though it could not fully quantify BSA, a tiny quantity of BSA fouled inside was visualized at a higher resolution than ever. Hence, it was concluded that the combination of CLSM and STORM was efficient for the analysis of foulants on the surface of and inside the membrane.
