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 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 LtdItem 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