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  • Item
    Removal of toxic arsenic from aqueous media using polyphenylsulfone/cellulose acetate hollow fiber membranes containing zirconium oxide
    (Elsevier B.V., 2020) Kumar, M.; Isloor, A.M.; Somasekhara Rao, T.; A.F., A.F.; Farnood, R.; Nambissan, P.M.G.
    Arsenic is one of the highly dangerous metalloid present in the polluted water, it's effective and economical removal is one of the major challenges to the researchers. It was planned to prepare hollow fiber membranes using polyphenylsulfone (PPSU) as a polymer, cellulose acetate (CA) and cellulose acetate phthalate (CAP) as additives with increased dosages (0.6, 1 and 1.5 wt%) of zirconium oxide (ZrO2) nanoparticle. The fabricated hollow fiber membranes were characterized by SEM, AFM, zeta potential, ATR-FTIR and XPS to analyze the membrane's morphologies (cross-section and surface), topography, surface charge and assessment of different functional groups. As used ZrO2 was characterized by TEM and XRD to analyze the morphology and crystallinity. The positron annihilation lifetime spectroscopy (PALS) analysis was carried out for neat and ZrO2 contained membranes, to study the expansion of free-volume in membrane morphology. Leaching studies of the used zirconium with respect to different pH from the ZrO2 contained hollow fiber membrane was also examined. The enhancement of membrane hydrophilicity was confirmed by contact angle, porosity, water uptake and pure water permeability measurements. Membranes prepared by 1 wt% of ZrO2 in PPSU/CA (PZCA-1) and 0.6 wt% of ZrO2 in PPSU/CAP (PZCAP-0.6) were proved to be efficient as arsenic removal membranes (i.e. PZCA-1 as 87.24% and PZCAP-0.6 as 70.48% and permeability of 89.94 L/m2h bar and 70.59 L/m2h bar respectively) using lab-prepared 1 ppm standard arsenic solution at pH range of 6.8 ± 0.2. Also, there is a decrease in the arsenic removal tendency was observed with the excessive dosages of ZrO2, which is due to the concentration polarization on surfaces of the membranes. Antifouling behavior of the prepared hollow fiber membranes was also studied using bovine serum albumin (BSA). © 2020
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    Effect of binary zinc-magnesium oxides on polyphenylsulfone/cellulose acetate derivatives hollow fiber membranes for the decontamination of arsenic from drinking water
    (Elsevier B.V., 2021) Kumar, M.; Isloor, A.M.; Todeti, S.R.; Nagaraja, H.S.; A.F., A.F.; Susanti, R.
    Arsenic contamination is continuously threatening the safety of drinking water in many parts of the world. The consumption of chronic arsenic contaminated drinking water can cause serious health related issues. Therefore, the synthesis of novel materials is very much essential for the selective removal of arsenic from aqueous solution. In the present investigation, the effect of increased concentrations (0.6, 1.0 and 1.5 wt%) of binary zinc-magnesium oxide (ZnO-MgO) on cellulose acetate (CA)/polyphenylsulfone (PPSU) and cellulose acetate phthalate (CAP)/PPSU hollow fiber membranes for arsenic removal was performed. As used ZnO-MgO was characterized by using x-ray diffraction (XRD), transmission electron microscopy (TEM) and particle size distribution. Fabricated hollow fiber membranes were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential, fourier transform infrared (FTIR), x-ray photoelectron spectrophotometer (XPS), thermogravimetric analysis (TGA) and antifouling studies. The results revealed that, there is significant enhancement in the overall performance of the ZnO-MgO containedmembranes. An enhancement of arsenic removal properties was demonstrated from 0.6 wt% of ZnO-MgO in CAP/PPSU (ZMCAP-0.6) membrane was 81.31% with the retention permeability of 69.58 L/m2h bar respectively. Similarly, 1 wt% of ZnO-MgO in CA/PPSU (ZMCA-1) was found to be 78.48% and 198.47 L/m2h bar respectively using 1 ppm laboratory prepared aqueous arsenic solution (pH 6.8 ± 0.2) at 1 bar transmembrane pressure. In addition, improved antifouling properties was noticed with an increased flux recovery ratio and enhanced thermal stability from ZnO-MgO contained membranes. Therefore, as fabricated ZnO-MgO contained membranes provided enhanced arsenic removal tendency without compromising the retention permeability. © 2020
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    Hydrophilic nano-aluminum oxide containing polyphenylsulfone hollow fiber membranes for the extraction of arsenic (As-V) from drinking water
    (Elsevier Ltd, 2021) Kumar, M.; Isloor, A.M.; Todeti, S.R.; A.F., A.F.; Farnood, R.
    In the present work, hollow fiber ultrafiltration membranes were fabricated by incorporating intensified dosages of nano?aluminum oxide (nano-Al2O3; 0.6 wt%, 1.0 wt% and 1.5 wt%) into cellulose acetate (CA)/polyphenylsulfone (PPSU) and cellulose acetate phthalate (CAP)/PPSU by non-solvent induced phase separation (NIPS) process. The topological structures and the morphologies were investigated using atomic force microscope (AFM) and scanning electron microscope (SEM). The crystalline and morphological structures of the nano-Al2O3 were investigated using X-ray diffraction (XRD) and transmission electron microscope (TEM) respectively. Fourier transform infra-red spectroscope (FTIR) and x-ray photoelectron spectroscopy (XPS) analysis have been carried out to validate the dosages of nano-Al2O3, CA and CAP on PPSU membranes. The membrane's surface charge measurement of 1.5 wt% of nano-Al2O3 in CA/PPSU (ALCA-1.5) was scrutinized by zeta potential analysis. Membranes removed more arsenate oxide as the removal rate from membranes ALCA-1.5 and 1.0 wt% of nano-Al2O3 in CA/PPSU (ALCA-1) was 98.67% and 94.89% with retention permeabilities of 88.41 L/m2h bar and 53.53 L/m2h bar respectively from laboratory prepared 1 ppm of aqueous arsenic solution with pH in the range 6.8 ± 0.2 at 1 bar transmembrane pressure. In addition, membrane's antifouling analysis was performed using laboratory prepared 0.8 g/L (Bovine Serum Albumin) BSA as standard protein solution. © 2021 Elsevier Ltd