Faculty Publications
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Item Improved separation of dyes and proteins using membranes made of polyphenylsulfone/cellulose acetate or acetate phthalate(Springer Science and Business Media Deutschland GmbH, 2020) Kumar, M.; Isloor, A.M.; Todeti, S.R.; Gnani Peer Mohamed, G.P.S.; Siddique, I.; A.F., A.F.; Asiri, A.M.Industrial wastewater often contains xenobiotics such as heavy metals, dyes and proteins, yet there is a lack of efficient cleaning methods. Therefore, here we fabricated hollow fiber membranes using polyphenylsulfone containing 1, 3 and 5 wt% of cellulose acetate and cellulose acetate phthalate by non-solvent induced phase separation. Membrane morphology was characterized by field emission scanning electron microscopy. The hydrophilicity of the membranes was measured by contact angle, water uptake and porosity measurement. The thermal miscibility of the membrane with additives was assessed by thermogravimetric analysis. Hollow fiber membranes were tested for separation of azo dyes, e.g., reactive orange 16 and reactive black 5, and of proteins: bovine serum albumin, egg albumin and pepsin. Results show increasing rejection of dyes and proteins with the content of cellulose acetate and cellulose acetate phthalate. Water permeability was 41.26 L/m2 h bar for the polyphenylsulfone membrane, 64.47 L/m2 h bar for the polyphenylsulfone/5 wt% cellulose acetate membrane and 72.60 L/m2 h bar for the polyphenylsulfone/5 wt% cellulose acetate phthalate membrane. © 2020, Springer Nature Switzerland AG.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). © 2020Item 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. © 2020Item Hydrophilic polydopamine/polyvinylpyrrolidone blended polyphenylsulfone hollow fiber membranes for the removal of arsenic-V from water(Elsevier Ltd, 2023) Kumar, M.; Isloor, A.M.; Nayak, M.C.S.; Todeti, S.R.; Padaki, M.; A.F., A.F.The demand for fresh drinking water is sky rocketing with the world's increasing population, urbanization and various industrial growth. However, toxic heavy metals and metalloids like arsenic is contaminating the drinking water. Arsenic is poisonous, carcinogenic and mutagenic for millions of population. We hereby proposing in-house fabricated novel hollow fiber membranes using polyphenylsulfone (PPSU) and pore-forming agent polyvinylpyrrolidone (PVP) along with increased concentrations of bio-inspired hydrophilic additive polydopamine (PDA) for removal of arsenic-V from the drinking water. The crystallinity of PDA was interpreted by X-ray diffraction. The morphology, topology and membrane surface chemistry of fabricated membranes were evaluated by scanning electron microscopy, atomic force microscopy, thermogravimetric analysis, fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy. The results indicated that, for the PDA-contained membranes overall performance was increased in terms of membrane hydrophilic characteristics and rejection efficacy. A 3 wt% of PDA in PPSU/PVP (PDA-3) executed enhanced arsenate (As-V) removal as high as 87.15% with flux of 31.80 L/m2h, which was higher than the neat membrane (PDA-0) as 67.70% with flux of 15.07 L/m2h for 5 mL/L arsenic-V aqueous solution at 0.2 MPa transmembrane pressure. Improved antifouling properties were observed from PDA-contained hollow fiber membranes, as evidenced by the improved flux recovery ratio and superior thermal stability. The mechanical properties (tensile strength) of pristine and PDA-contained membranes was also investigated. © 2023