Faculty Publications
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Item Fundamentals and basics of reverse osmosis(Elsevier Inc., 2019) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Farnood, R.This chapter endows an inclusive introduction to the fundamentals and basics of the reverse osmosis (RO) process. It starts from the short history, plants, and theoretical contextual of RO. A concise summary of the recent advances in RO membranes and materials then follows. Lastly, the usage of different types of modules such as spiral wound prepared from flat sheet membranes and hollow fiber membranes used in RO desalination is discussed. © 2020 Elsevier Inc. All rights reserved.Item Reverse osmosis pretreatment techniques, fouling, and control strategies(Elsevier Inc., 2019) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Farnood, R.In recent times, many commercial-scale seawater desalination plants have been constructed in water-stressed countries, which are expected to increase in the near future to increase the availability of potable water. In spite of many developments in the desalination technologies, seawater desalination using reverse osmosis (RO) membrane is being considered as the state-of-the-art technology. However, there are also some limitations to the RO membrane desalination such as the unavoidable membrane fouling, which increase the operating cost and transmembrane pressure. Here, we review the potential way to the RO membrane fouling control strategies, which includes the role of advanced materials, surface modification and feed water pretreatment that are emphasized based on the extensive up-to-date literature. © 2020 Elsevier Inc. All rights reserved.Item Nanocomposite Membranes for Proton Exchange Membrane Fuel Cells(wiley, 2023) Satishkumar, P.; Isloor, A.M.; Farnood, R.The development of green technologies like fuel cell is need of the day because of their zero emission and as an efficient technology to produce electrical energy. Among the different varieties of fuel cells, enhancing the performance of proton exchange membrane (PEM) fuel cell is emphasized because of their numerous advantages such as easy portability, less corrosive nature, and leakage-free convenient setup. Generally used Nafion membranes in PEM fuel cells show few limitations such as the inability to work at high temperature and low relative humidity. Nanocomposite membranes play an indispensable role in overcoming these flaws. Incorporating numerous nanoadditives like silica, titanium dioxide, zirconium dioxide, graphene oxide, zirconium phosphate, heteropolyacids, and metal-organic frameworks into the variety of polymer matrix such as Nafion, sulfonated polybenzimidazole, polysulfone, sulfonated poly(ether ether ketone), and biopolymers involving polyvinyl alcohol, chitosan is assessed with its characteristic properties of proton conductivity, mechanical stability, oxidative stability, and power density. Nanocomposite membranes aid to increase the mechanical stability of the PEMs by the combination of two or more polymer layers and especially with a solid support layer. Development of natural, biodegradable polymer-based PEMs with enhanced proton conducting ability and chemical stability was possible only because of the nanocomposite model; otherwise, it was not possible. Certain hygroscopic inorganic additives improved the water uptake capacity of the nanocomposite membranes even at elevated temperatures. A large pool of nanocomposite membranes that can meet the desired characteristics of PEMs for fuel cell applications is reviewed in detail. © 2023 Scrivener Publishing LLC.Item Continuous Production of Clean Hydrogen from Wastewater by Microbial Usage(wiley, 2023) Satishkumar, P.; Isloor, A.M.; Farnood, R.Biohydrogen production from wastewater is a prominent way to address escalating global energy demand and alarming environmental pollution. The need for renewable, sustainable, economic, and environment-friendly pathways for energy generation is fulfilled by biohydrogen evolution. Wastewaters contain a vast array of organic contents, as well as microbes and are a suitable source for bioreactors. Treatment of wastewaters with hydrogen-generating bacteria significantly aids its purification process by reducing chemical oxygen demand with simultaneous hydrogen generation. Among the various methods that are available for hydrogen production from microbes, photo fermentation, dark fermentation, and microbial electrolysis cells are discussed thoroughly. Continuous hydrogen generation systems are most suitable for large scale commercial production. Uniform product quality is obtained in the case of continuous systems. Microbial electrolysis cells have been found to yield exceptionally good hydrogen purity. A variety of factors that affect hydrogen evolution in all the techniques are reviewed in detail. © 2023 Scrivener Publishing LLC. All rights reserved.Item Expansive Applications of Chitosan and Its Derivatives in Membrane Technology(CRC Press, 2023) Satishkumar, P.; Isloor, A.M.; Farnood, R.The membrane separation technique is gaining constant importance due to its efficacy and wide applications. Among the large pool of polymers that are available for membrane preparation, biopolymers like chitosan are of great interest. Chitosan is biodegradable, nontoxic, and shows good biocompatibility. Chitosan membranes have been utilized in a variety of water purification applications which include the removal of dye, heavy metals, and proteins from wastewater. Chitosan membranes also have been used in forward osmosis desalination and oil-in-water emulsion separation. In carbon dioxide capture and air filtration, chitosan membranes have been employed. Proton exchange membranes made up of chitosan have been reported in the case of fuel cells. The biocompatibility of chitosan helped in the development of membranes for bone generation. This review chapter encompasses a large number of applications in which chitosan membranes have been productively utilized. © 2024 selection and editorial matter, Anil Kumar Pabby; S. Ranil Wickramasinghe; and Ana- Maria Sastre; individual chapters, the contributors.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 Tuning the surface properties of Fe3O4 by zwitterionic sulfobetaine: application to antifouling and dye removal membrane(Springer, 2020) Gnani Peer Mohamed, G.P.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; Farnood, R.In this paper, zwitterionic polysulfobetaine@Fe3O4 (PSBMA@Fe3O4) nanoparticles were synthesized via covalent grafting and free radical polymerization and characterized. The PSBMA@Fe3O4 noparticles had a zeta potential of ? 36 mV (pH 6.3), which guaranteed the high colloidal stability. The as-synthesized nanoparticles were employed as a nanofiller to prepare superior antifouling polysulfone hybrid hollow fiber membranes. The FM-2 membrane exhibited the maximum pure water permeability of 61.1 L/m2 h bar with humic acid (HA) removal efficiency of 98%. The fouling resistance was evaluated using HA as a foulant, and the results suggested that the FM-2 membrane had less amount of HA adsorption with flux recovery ratio of 88.4%. Furthermore, the FM-2 membrane was demonstrated the reactive black-5 and reactive orange-16 removal of above 99% and 84% without much reduction in the dye solution permeability. © 2020, Islamic Azad University (IAU).Item One-step synthesis of zwitterionic graphene oxide nanohybrid: Application to polysulfone tight ultrafiltration hollow fiber membrane(Nature Research, 2020) Gnani Peer Mohamed, G.P.; Isloor, A.M.; A.F., A.F.; Farnood, R.In this paper, novel zwitterionic graphene oxide (GO) nanohybrid was synthesized using monomers [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) and N,N?-methylenebis(acrylamide) (MBAAm) (GO@poly(SBMA-co-MBAAm), and incorporated into polysulfone (PSF) hollow fiber membrane for the effectual rejection of dye from the wastewater. The synthesized nanohybrid was characterized using FT-IR, PXRD, TGA, EDX, TEM and zeta potential analysis. The occurrence of nanohybrid on the membrane matrix and the elemental composition were analyzed by XPS. The as-prepared tight ultrafiltration hollow fiber membrane exhibited high rejection of reactive black 5 (RB-5, 99%) and reactive orange 16 (RO-16, 74%) at a dye concentration of 10 ppm and pure water flux (PWF) of 49.6 L/m2h. Fabricated nanocomposite membranes were also studied for their efficacy in the removal of both monovalent (NaCl) and divalent salts (Na2SO4). The results revealed that the membrane possesses complete permeation to NaCl with less rejection of Na2SO4 (<5%). In addition, the nanocomposite membrane revealed outstanding antifouling performance with the flux recovery ratio (FRR) of 73% towards bovine serum albumin (BSA). Therefore, the in-house prepared novel nanocomposite membrane is a good candidate for the effective decolorization of wastewater containing dye. © 2020, The Author(s).Item 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 Catalyst- and Stabilizer-Free Rational Synthesis of Ionic Polymer Nanoparticles in One Step for Oil/Water Separation Membranes(American Chemical Society, 2022) Gnani Peer Mohamed, S.I.; Isloor, A.M.; Farnood, R.Ionic polymer nanoparticles (IPNs) were synthesized in one pot by quaternization precipitation polymerization (QPP) as a novel polymerization technique. QPP eliminated the usage of high-cost ionic monomers and reduced the number of steps for the preparation of IPN. The monomers 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 4-vinylbenzyl chloride (VBC) polymerized in the presence of azobisisobutyronitrile (AIBN) and underwent quaternization simultaneously, which yielded ionic poly(DMAEMA-co-VBC) nanoparticles in one step with the size of 50-80 nm without any stabilizer and catalyst. Similarly, 4-vinylpyridine (VP) and VBC polymerized in the presence of AIBN and underwent quaternization simultaneously, which yielded ionic poly(VP-co-VBC) nanoparticles in one step with the size of 70-90 nm without any stabilizer and catalyst. The as-synthesized IPN was further utilized for the fabrication of hydrophilic nanocomposite ultrafiltration membranes for oil/water separation. Fabricated hybrid membranes were characterized and studied for oil rejection properties. It exhibited an oil rejection of >96% with a pure water permeability of 219 L/m2 h bar. © 2022 American Chemical Society.