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

Binary metal oxides incorporated polyethersulfone ultrafiltration mixed matrix membranes for the pretreatment of seawater desalination

“…18 Additionally, swelling property of SPEEK with binary metal oxides tends to loosen the polymer matrix arrangement hence resulted in fast transport of water molecules across the membrane. 22 These results are in good agreement with the mean pore radius analysis as listed in Table 1. Figure 6b shows the protein rejection of pristine PES and modified PES membranes.…”

“…28 both SPEEK and binary metal oxides, which disrupts the PES-NMP solvent interaction and allows the nonsolvent into PES Matrix under phase separation process. 22 From Figure 5, the presence of metal oxides is clearly visible on the surface and cross-section of both binary metal oxide incorporated PES and SPEEK/PES MMMs. It is due to the movement of hydrophilic TiO 2 /ZrO 2 /ZnO nanoparticle toward the nonsolvent (water) which resulted in the nanocomposites being anchored to the PES membrane surface during phase inversion step.…”

“…SPEEK modified PES MMMs showed better antifouling and solute retention properties. 22 For pristine PES casting dope solution, 18 wt% of dried PES powder was dissolved in 82 wt% of NMP under magnetic stirrer for 24 h at a temperature of 60 C. In the case of MMMs, known amount of binary metal oxide was dispersed initially in NMP using ultrasonication for 1 h. Next, appropriate amount of SPEEK and PES polymer was added onto the binary metal oxide dispersed solution and allowed to dissolve at a temperature of 60 C for 24 h. Then, the dope solution was ultrasonicated again to disperse the binary metal oxide in polymer chains. Degassing was carried out before casting the dope solution.…”

“…In order to study the fouling effects, final membrane water permeability (L aw ) was again measured and the flux reduction percentage was calculated using the Equation (4). 22 Flux reduction percentage FRP…”

“…The water recovery percentage from the seawater filtration was calculated by Equation (5). 22 Water recovery % ð Þ=…”