Reversible and irreversible fouling of ultrafiltration ceramic membranes by model solutions

Although ceramic membranes are of increasing interest for drinking water treatment, there is little information available regarding their fouling behavior in this context. The objective of the current investigation was to understand the fouling behavior of ceramic membranes on a fundamental level with foulants that have been identified as problematic for polymeric membranes in drinking water treatment. All solutions showed cake filtration except humic acid and the combination of humic acid and bovine serum albumin (BSA), which showed intermediate and complete blocking filtration, respectively. Silica played a substantial role in increasing rates of flux decline. BSA was the only foulant that significantly increased the hydrophobicity of the membrane, suggesting that the contact angle of the fouled membrane is not an indication of fouling severity or reversibility. Synergistic fouling effects were observed when model solutions were combined. These results will be helpful for the application of ceramic membranes in drinking water treatment.