On-line biofilm strength detection in cross-flow membrane filtration systems.

A fluid dynamic gauging (FDG) technique was used for on-line and in situ measurements of Pseudomonas aeruginosa PAO1 biofilm thickness and strength on flat sheet polyethersulphone membranes. The measurements are the first to be successfully conducted in a membrane cross-flow filtration system under constant permeation. In addition, FDG was used to demonstrate the removal behaviour of biofilms through local biofilm strength and removal energy estimation, which other conventional measurements such as flux and TMP cannot provide. The findings suggest that FDG can provide valuable additional information related to biofilm properties that have not been measured by other monitoring methods.