Accelerated testing for fouling of microfiltration membranes using model foulants

• Fouling of hollow fiber membranes was evaluated by means of accelerated testing experiments.
• A simple model based on pseudo-cake filtration model was applied to estimate the normalized fouling rates, θ/J2.
• In the accelerated testing of membranes, the fouling rate was less sensitive to foulant concentration than to flux.

Hollow fiber microfiltration (MF) membranes have been widely employed for water and wastewater treatment. Nevertheless, membrane fouling is still one of the most serious issues in operating hollow fiber membrane systems. In this research, fouling of hollow fiber MF membranes was evaluated by means of accelerated testing experiments. A single fiber filtration unit was used to perform the fouling experiments in an accelerated way. Permeate flux and foulant concentrations were used as fouling control parameters to adjust the rate of fouling. Four model foulants used were kaolin, silica, natural organic matters (NOM), and alginate. A simple theoretical model was applied to investigate the fouling characteristics of the membrane by the model foulants. The analysis showed that there was a nonlinear correlation between the fouling rate and the fouling control parameters. The “normalized” fouling rate, θ/J2, was found to be useful to quantify the fouling rate and to implement a long-term simulation of TMP changes.