Advanced surface-sensitive techniques for characterizing membrane surface phenomena and responsive membrane polymers.

摘要

Membrane water treatment processes suffer severely from (bio)fouling phenomena, defined as an undesired deposition and build-up of adsorbed materials, which alters the membrane surface and causes the clogging of membrane pores and hence a reduction of the membrane flux. Elucidating the phenomena that take place on the membrane surface during (bio)fouling requires the use of adequate characterization techniques. Membrane autopsy is the most common technique used to identify and determine the causes of fouling events in membrane systems making use of fouled membranes that already exhibit a poor performance, and certainly provide some hints on how and when to apply corrective measures. However, the control of membrane (bio)fouling is directly related to first the (bio)foulant agent — membrane surface interactions arising at a much earlier stage during the process, and neither the earlystage biofoulant-membrane surface interactions nor the conditions leading to their occurrence are completely understood, yet. Therefore, there is a strong need for real time and on line monitoring of these phenomena providing a fundamental understanding and an appropriately fast response for operators to act and adjust their operational conditions in order to minimize the effect of (bio)fouling on the membrane process. This study presents surface plasmon resonance (SPR), quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry as advanced surface-sensitive techniques for the real time and non-invasive characterization of (bio)foulant-membrane surface interactions. These techniques will also be shown to prove powerful for characterizing and monitoring antifouling measures, such as responsive membrane surface layers.