Faculty Publications
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Item Preparation and performance studies of polysulfone-sulfated nano-titania (S-TiO2) nanofiltration membranes for dye removal(Royal Society of Chemistry, 2015) Pereira, V.R.; Isloor, A.M.; Bhat, K.U.; A.F., A.F.; AlObaid, A.; Fun, H.-K.Polysulfone nanofiltration membranes containing sulfated nano-titania (S-TiO2) were fabricated, with the aim to enhance the membrane properties along with the possible rejection of Methylene Blue (MB) dye by membranes. Initially S-TiO2 was synthesized from nano TiO2 by the action of sulfuric acid. The synthesized S-TiO2 was characterized by Fourier Transform Infrared spectroscopy (FT-IR), Energy Dispersive Spectrophotometry (EDS) and Transmission Electron Microscopy (TEM) analysis. S-TiO2 was added in increasing concentrations into the membranes and its effect on the performance of the membranes was evaluated. The synthesized membranes were characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Polysulfone membranes containing S-TiO2 showed enhancement in properties in terms of hydrophilicity, water uptake, mechanical strength, improved pure water flux (PWF), antifouling nature and high Flux Recovery Ratio (FRR). The polysulfone membranes with S-TiO2 showed 99% rejection for BSA (Bovine Serum Albumin) protein molecules during BSA filtration. The prepared membranes were used for the removal of MB dye from aqueous solutions. A maximum of 90.4% rejection was obtained for MB for the membrane having 2.0 wt% of S-TiO2 under UV light radiation. This approach showed that polysulfone-S-TiO2 membranes displayed good efficiency for dye removal and can be effectively used for the removal of MB dye from aqueous solutions under suitable conditions. © The Royal Society of Chemistry.Item Novel hybrid photocatalytic reactor-UF nanocomposite membrane system for bilge water degradation and separation(Royal Society of Chemistry, 2015) Moslehyani, A.; A.F., A.F.; Othman, M.H.D.; Isloor, A.M.This study focuses on the design and performance of a hybrid system consisting of a photocatalytic reactor and ultrafiltration permeation cell. Initially, an ultraviolet (UV) lamp was installed in the photocatalytic reactor to decompose the bilge organic pollutants in the presence of 200 ppm titanium-dioxide (TiO2). Individual hydrocarbon compounds of bilge water samples were identified by gas chromatography-mass spectrometry (GC-MS) analysis. Two types of membrane, which are a pure polyvinylidene fluoride (PVDF) membrane and PVDF/modified halloysite nanotube clay (M-HNTs) nanocomposite membrane were fabricated aiming to enhance the rejection, flux and fouling resistance for full filtration of pollutants from the photocatalytic reactor. The membranes were characterized by Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Furthermore, GC-MS analysis showed that, over 90% bilge decomposition occurred by a photocatalytic reaction. The TiO2 cross-over during permeation was detected by using an atomic absorption spectrophotometer (AAS), which proved that, TiO2 rejection was more than 99% for the nanocomposite membrane. A UV- vis spectrophotometer confirmed over 99% rejection of decomposed bilge hydrocarbons via the nanocomposite membrane with 1.0 wt% of M-HNTs incorporated in the PVDF matrix. This journal is © The Royal Society of Chemistry 2015.Item Humic Acid Based Biopolymeric Membrane for Effective Removal of Methylene Blue and Rhodamine B(American Chemical Society service@acs.org, 2015) Shenvi, S.S.; Isloor, A.M.; A.F., A.F.; Shilton, S.J.; Al-Ahmed, A.Humic acid was immobilized on a polypropylene supported sodium alginate/hydroxyethyl cellulose blend membrane in the current work. The adsorption property of this membrane for the removal of cationic dyes, namely, methylene blue (MB) and rhodamine B (RhB), was extensively studied. Batch-adsorption experiments were conducted to investigate the adsorption behavior of dyes on the membrane with variation in adsorbent mass, initial dye concentration, pH, time, and temperature. The membranes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM). Prepared membranes showed more than 98% removal capacity for both dyes under optimal conditions. Kinetic experiments revealed that the pseudo second order model exhibited the best correlation with the adsorption data. Dubinin-Radushkevich model indicated that the adsorption of dyes onto the membrane surface was by simple physisorption. The membrane was easily regenerated by simple acid treatment, and its efficiency remained significant even after four adsorption cycles. © 2015 American Chemical Society.Item Novel polyphenylsulfone (PPSU)/nano tin oxide (SnO2) mixed matrix ultrafiltration hollow fiber membranes: Fabrication, characterization and toxic dyes removal from aqueous solutions(Elsevier B.V., 2019) Nayak, M.C.; Isloor, A.M.; Siddique, I.; Balakrishna Prabhu, B.; Ismail, N.I.; Asiri, A.M.Novel polyphenylsulfone (PPSU)/nano tin oxide (SnO2) mixed matrix hollow fiber membranes (HFMs) were fabricated by dry-wet spinning via phase separation method. In the current research, reported the contrast between neat PPSU membrane and nanocomposite membranes (PPSU/SnO2), to determine the toxic reactive dyes namely, reactive black-5 (RB-5) and reactive orange-16 (RO-16) removal ability from the aqueous media. Scanning electron microscopy (SEM) was used to observe the HFMs cross-sectional morphological changes and surface roughness parameters of membranes were analyzed using atomic force microscopy (AFM). The surface wettability ability of HFMs was examined with a contact angle, water uptake, and porosity measurements. The cross-flow filter unit was engaged to quantify the water permeability, anti-fouling ability as well as the dye rejection ability of fabricated membranes. With increasing the SnO2 NPs wt% in PPSU polymer matrix the membrane performance was enhanced continuously, it became evident that the incorporated SnO2 NPs plays main role in membrane performance. Added, water-soluble poly (vinylpyrrolidone) (PVP) can also impact the pore morphology in membranes. At the end, PS-3 membrane exhibited lower contact angle (63.7 0), higher water uptake (74.8%), porosity (84.1%), pure water flux 362.9 L/m2 h, and high potential for dyes rejection application, of about >94% for RB-5, and >73% for RO-16 dye, respectively. From the preliminary results, it can be stated that the usage of SnO2 NPs in membrane technology become effective towards wastewater treatment. © 2019 Elsevier B.V.Item Polyphenylsulfone/multiwalled carbon nanotubes mixed ultrafiltration membranes: Fabrication, characterization and removal of heavy metals Pb2+, Hg2+, and Cd2+ from aqueous solutions(Elsevier B.V., 2020) Chandrashekhar Nayak, M.; Isloor, A.M.; Siddique, I.; Lakshmi, B.; Marwani, H.M.; Khan, I.Polyphenylsulfone/multiwalled carbon nanotubes/polyvinylpyrrolidone/1-methyl-2-pyrrolidone mixed matrix ultrafiltration flat-sheet membranes were fabricated via phase inversion process to inspect the heavy metals separation efficacy from aqueous media. Fabricated membranes cross-sectional morphological changes and the topographical alterations were assessed with Scanning electron microscopy (SEM) and atomic force microscopy (AFM). Particularly, MWCNTs assisted membranes exhibited better permeability ability as well as heavy metal removal enactment than virgin membrane. The dead-end filter unit was engaged in current research to examine the permeability and heavy metal removal competence of membranes. With the continuous enhancement of MWCNTs wt% in a polymer matrix, significant enhancement was observed with pure water flux study, from 41.69 L/m2 h to >185 L/m2 h as well as with the heavy metals separation study. Added additive MWCNTs can impact the pore sizes in membranes. The heavy metal separation results achieved, the membrane with 0.3 wt% of MWCNTs (PCNT-3) exhibited >98%, >76% and >72% for Pb2+, Hg2+ and Cd2+ ions, respectively. Overall, MWCNTs introduced PPSU membranes exposed best outcomes with heavy metals contained wastewater treatment. © 2019 The AuthorsItem 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. © 2023Item Sustainable waste water purification via integration of novel COF@UiO-66 dual-layer PVDF/PEI hollow fiber membranes(Elsevier B.V., 2025) Prabhakar, N.; Isloor, A.M.; Othman, M.H.D.; A.F., A.F.In the present study, dual-layer (polyvinylidene fluoride (PVDF)/ polyether imide (PEI) blend membranes were fabricated by coextrusion technique, with varying loadings (0–1.5 wt%) of covalent organic framework (COF) grafted UiO-66, for dye and heavy metal ion removal. UiO-66-NH2 was chosen for its excellent surface area and water stability, which can enhance the water permeability through the membrane without getting degraded over a period of time. The structures of the synthesized UiO-66-NH2 and COF@UiO-66 were confirmed by characterizations like scanning electron microscopy (SEM), FTIR (Fourier Transform Infrared Spectroscopy), and XRD (X-ray Diffraction). The membrane fabricated with the synthesized additive in the outer layer, was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM) for the surface topography and morphology. The incorporation of the additive significantly affected the hydrophilicity, porosity, and surface area of the membrane, resulting in improved permeability and rejection, along with imparting relatively good antifouling nature to the membrane. Membrane with outer dope flow rate of 2 mL/min and an optimized loading of the additive (1.0 wt.%) displayed a water permeability of 117.5 Lm?2 h?1 bar?1, whereas the neat membrane showed only 60 Lm?2 h?1 bar?1. The dyes, Congo red and reactive black-5, showed rejections of 99.1 %, and 97.96 % respectively. Whereas, the heavy metal ions mercury and lead showed 69.58 %, and > 99.9 % in the complexed state with humic acid for the optimized membrane, along with a bovine serum albumin (BSA) fouling rejection ratio of 74.22 %. Whereas the neat membrane without the MOF additive showed 89 %, 79 %, 75 %, and 43 % rejections for reactive black 5, congo red, lead, and mercury ions, respectively, with an FRR of only 57 %. © 2025 Elsevier B.V.