Impact of transmembrane pressure (TMP) on membrane fouling in microalgae harvesting with a uniform shearing vibration membrane system

A uniform shearing vibration membrane system can mitigate membrane fouling during algae filtration. In this paper, the effects of transmembrane pressure (TMP) on the membrane filtration performance at 8 kPa, 9 kPa and 10 kPa were investigated. The results of membrane fouling mechanisms predicted by Hermia's model surmised that membrane fouling is principally caused by the cake layer model, and the application of the Unified Membrane Fouling Index for quantitative evaluation of antifouling properties substantiating membranes in sub-critical condition exhibited superior antifouling properties. The reversible membrane fouling was largely dependent on polysaccharides due to size exclusion. Proteins tended to block the membrane pores and to cause irreversible fouling. It was also observed that high-molecular weight (> 100 kDa) extracellular organic matters contributed a significant portion of membrane fouling. For greater insight, the CRiteria Importance Through Intercriteria Correlation (CRITIC) method was administered; it could be concluded that the removal of proteins was more responsible for the total fouling resistance than was the removal of polysaccharides, especially for membranes at the TMP of 9 kPa.