Influence of various shapes of alumina nanoparticle in integrated polysulfone membrane for separation of lignin from woody biomass and salt rejection.

Lignin valorization is essential in proposing an economic perspective as a raw material for valuable compounds. The bio-refineries require adequate processing to improve the high purity of lignin. Meanwhile, nanofiltration is fascinated attention to obtain high purity value-added products. The effect of alumina nanoparticles on the fabrication of mixed matrix membranes (MMM) has contributed to improvising filtration performance. However, incorporating nanoparticles is a significant issue regarding appropriate size and shape integrated into membrane for better filtration efficiency. The influence of shapes of alumina nanoparticles has been investigated into polysulfone (PSf) membranes for salt and lignin separation. The morphology of alumina was tailored with spindle, cubic, and spherical shapes synthesized at a different calcination temperature of 250, 500, 700 and 900 °C, respectively. The phase transitions were confirmed in X-ray diffraction (XRD) analysis, and the shape of the nanoparticles was observed in a high-resolution transmission electron microscope (HRTEM). The separation efficiency of membranes was tested with salt rejection using sodium sulfate, calcium chloride, potassium sulfate, and sodium chloride. The lignin was extracted from prehydrolysed sawdust, and the synthetic lignosulfonic acid sodium salt solution was separated. The higher lignin rejection of 98.6% and 97.9% were obtained for cubic shaped gamma phase alumina mixed matrix membrane. The high rejection of lignin occurred due to narrow pores channels that could resist the transfer of lignin through the membrane. The results proved that the controllable organization of PSf/alumina mixed matrix membranes could apply for lignocellulose compounds with good efficiency.

Nano-curcumin incorporated polyethersulfone membranes for enhanced anti-biofouling in treatment of sewage plant effluent.

Biofouling is a severe problem in membrane systems which hampers their broad applications because it requires regular chemical cleaning, reduces membrane life, and also decreases product quality. In this study, nanocurcumin (CCM) was prepared by sonication-assisted wet-milling technique and then incorporated in polyethersulfone (PES) membrane to enhance the anti-biofouling property. TEM analysis of the curcumin showed that nanomaterials are spherical. FTIR studies confirmed that the presence of CCM nanomaterial in PES membrane. Zone inhibition studies revealed that PES/CCM nanocomposite membranes exhibited the better anti-biofouling propensity against Escherichia coli and Pseudomonas aeruginosa. Static adhesion studies also showed that PES/CCM nanocomposite membranes prevented the attachment and proliferation of E. coli cells. Also, PES/2 wt% CCM nanocomposite membrane had a high thermal degradation temperature of 575.62 °C and tensile strength of 1.87 MPa. Moreover, addition of CCM nanomaterial in casting solution altered the membrane morphology and hydrophilicity. Further, pure water flux was increased up to 64.48 L·m-2·h-1 for PES/2 wt% CCM nanocomposite membrane. Filtration of raw sewage treatment plant effluent was also carried out. The incorporation of curcumin in membranes was effectively improved the antifouling tendency without compromised affecting the chemical oxygen demand reduction. This study highlights the anti-biofouling potential of CCM incorporated PES nanocomposite membranes, which could be utilized for various filtration applications.