Harvesting of microalgae Coelastrella sp. FI69 using pore former induced TiO2 incorporated PES mixed matrix membranes

Abstract

BACKGROUND: Extracellular polymeric substances and microalgae stimulate membrane fouling during harvesting. The objective of the study was to compare the effect of pore formers on TiO2 embedded polyethersulfone mixed matrix membranes (MMMs) to harvest Coelastrella sp. FI69. The study experimented with hydrophilic additive (polyethylene glycol), polyelectrolyte additive (polyethylenimine), inorganic additive (zinc chloride) and charged polymer (sulfonated polyetherether ketone (SPEEK)) as pore formers. RESULTS: It was found that SPEEK/TiO2 combination enhanced the hydrophilic property of the PES membrane surface. Also, contact angle value (55.22°) was decreased by 1.38 times that of a neat PES (76.63°) membrane. Morphology studies indicated that the TiO2 particles dispersed well in the PES membrane matrix along with pore formers. The existence of super hydrophilic TiO2 supported the restriction of microalgae cell attachment on the membrane surface. The filtration of alginic acid sodium solution analysis showed that PES/SPEEK/TiO2 and PES/PEG/TiO2 membranes support higher flux with minimal fouling percentage. Microalgae filtration studies indicated that synergistic effect of both SPEEK and TiO2 on PES membrane exhibited higher water recovery percentage of 96% and equilibrium flux of 66 L m-2 h-1. CONCLUSION: Fouling propensity is significantly reduced in modified membranes. Future research on scale-up of membranes for further microalgae dewatering applications is recommended. © 2017 Society of Chemical Industry.