cheryan m 1998 ultrafiltration and microfiltration handbook

Microalgae-based products such as food, feed and nutraceutical supplements, cosmetics and even biofuels have gained growing interest leading to an increase in large-scale cultivation of microalgal biomass ( Barkia et al., 2019 Spolaore et al., 2006). Overall, combination of low TMP with aeration offers lowest energy input. In terms of energy consumption, it was observed that the specific energy consumption for the ULPM were very low of up to 4.4 × 10 −3 kWh/m 3. In this study, aeration was introduced as membrane fouling control to scour-off the foulant from membrane surface and pores. Membrane fouling is the biggest drawback of membrane system as it would reduce the membrane performance. However, it was found that membrane fouling was more vulnerable at low TMP due to poor foulant scouring from a low crossflow velocity in which up to 56 % of permeability losses were observed. The Chlorella vulgaris broth permeabilities decreased from 16 to 296 and 251 L/m 2hrbar for corresponding TMPs for system with and without aeration, respectively. Results showed that membrane compaction leads to up to 66 % clean water permeability loss when increasing the TMP from 2.5 to 19 kPa. In addition, membrane with high TMP would severely affect by membrane compaction. High TMP often associated with high pumping energy hence would increase the amount of energy consumed. ULPM offered various benefits especially in terms of reducing the energy consumption due to it operated under low transmembrane pressure (TMP). This study evaluated an energy-efficient microalga harvesting via ultra-low-pressure membrane (ULPM) filtration (<20 kPa) in combination with aeration. However, the high energy associated with microalgae harvesting becomes one of the bottlenecks. Microalgae-based products have gained growing interest leading to an increase in large-scale cultivation.

Cheryan m 1998 ultrafiltration and microfiltration handbook