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In this study, the morphology of the nanostructures is evaluated on the surface characterization and performance of the polyacrylonitrile (PAN) ultrafiltration mixed matrix membranes (MMM). To this end, silica nanoparticles (NPs) such as spherical (SiO2) and hexagonal mesoporous (MCM‐41) with high hydrophilicity were incorporated at 0.5, 1, and 2 wt%. Attenuated total reflectance‐Fourier transform infrared analysis illustrated the placement of NP on the surface of the MMM. Atomic force microscopy studies also showed that SiO2 NP added to PAN exhibited a smoother surface than MCM‐41 NP. Field‐emission scanning electron microscope analysis of the MMM identified that all membranes are composed of a finger‐like porous structure. Contact angle measurements indicate that the morphology of the NPs has no significant effect on MMM hydrophilicity. Moreover, the performance of the MMM was evaluated, and regardless of NP morphology, the MMM showed better permeate flux with increased loading. A higher pure water flux was observed in the PAN‐MCM41‐1% membrane (237 L/m2 h), possibly because of inherent porosity and high hydrophilicity of MCM‐41 compared to SiO2 NP. Further, the PAN‐SiO2‐1% membrane exhibited superior antifouling properties due to a lower surface roughness. The present studies reveal that the morphology of the NP greatly influence on the structure, permeation, and antifouling properties of PAN membranes. [ABSTRACT FROM AUTHOR]

Novel mixed matrix membranes (MMMs) were fabricated using Fe3O4, and Al2O3 nanoparticles (NPs) were added to the polysulfone (PSf) and N‐methylpyrrolidone (NMP) solution. The nanocomposite membranes were fabricated using the NIPS (non‐solvent induced phase separation) method. In order to create preferential permeation pathways for water across the MMMs, membrane formation is accomplished with an external magnetic field. Using magnetic casting cause the targeted placement of NPs in the best location and orientation. The performance of the prepared membranes was examined in terms of pure water flux and fouling parameters. Magnetic casting considerably increased pure water flux and decreased the total resistance of the optimum mixed matrix membrane, which contains 0.2% wt. of Fe3O4 NPs to 1175 L/m2h and 13.4 * 1011 (m−1), respectively. This is explained by the ordering of magnetic nanoparticles on the membrane sub‐layer cast under the magnetic field of 500 mT, which changed the sub‐layer structure. Less rough membrane surface of the mixed matrix membranes offered preferable anti‐fouling properties against fouling by BSA proteins. The characterization of fabricated membranes was carried out using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive X‐ray (EDX), and water contact angle measurement methods. [ABSTRACT FROM AUTHOR]

The goal of the current research is to simultaneously improve the fouling resistance and mechanical properties of polyacrylonitrile ultrafiltration membrane for membrane bioreactors (MBR) applications by a relatively easy method. For this purpose, amino‐functionalized carbon nanotubes (NH2‐MWCNTs) were employed, which have exceptional mechanical properties, hydrophilic functions, and good interaction with polyacrylonitrile. It was used to fabricate nanocomposite membranes with different MWCNTs contents. The rheological and thermodynamical aspects of the phase separation process were investigated to understand the mechanism of the membrane formation. The related characteristics including morphological, mechanical, and chemical properties of the membrane as well as its performance were studied. In the end, the synthesized membranes were used in an MBR setup for further investigations. The Pure water flux data shows considerable improvement from 810 LMH for the neat membrane to 1055 LMH for the 0.3 wt% NH2‐MWCNTs nanocomposite membrane. Mechanical enhancement was confirmed with about a 24% increase in the tensile strength and 61% for elongation at break. The membrane with 0.3 wt% NH2‐MWCNTs revealed the best porosity, fouling resistance, and performance in MBR with 95% flux recovery ratio and 64% improvement in permeated flux compared to the neat membrane. [ABSTRACT FROM AUTHOR]

The aim of this work was to synthesize nanocomposite membranes based on chitosan (CS) and cellulose acetate (CA) blends containing titanium dioxide (TiO2) nanoparticles and investigate their morphological, structural, mechanical, and thermal properties along with dye affinity ligand content for using potentially as bioadsorption applications. The samples were characterized by means of scanning electronic microscopy (SEM), energy dispersive X‐ray (EDX), Fourier transform infrared spectroscopy (FTIR), tensile, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and water contact angle (WCA). The SEM micrograph images showed a uniform and microporous morphology of the prepared membranes. FTIR analysis confirmed the presence of CA and TiO2 nanoparticles through the CS matrix in which the components used had good compatibility. The mechanical and thermal studies emphasized that strong interactions occurred between CS, CA, and TiO2 nanoparticles. Blending CS with CA and the addition of TiO2 nanoparticles enhanced the hydrophilic property of CS membranes, significantly. The CS/CA based nanocomposite containing 1.5 wt% of TiO2 nanoparticles showed the remarkable improvements in ultimate tensile strength values and an increase in stiffness more than three times compared to the neat CS membrane sample. Finally, considering the results of tensile test and immobilized Cibacron Blue F3G‐A (CB) content measurement, the nanocomposite samples denoted by (50/50) CS/CA/TiO2 (1.5%) were nominated as the promising material used for potentially bioadsorptive membrane. POLYM. COMPOS., 39:4452–4466, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the potential use of ozonation with pharmaceutical compounds on membrane bioreactor (MBR). The result has shown that high concentrations of pharmaceutical contaminants have caused destruction of cell wall, thereby reducing mixed liquor suspended solids (MLSS). It also resulted in high amounts of biopolymers in the presence of non-biodegradable pharmaceutical compound in MBR. As a result, biological removal decreased and membrane fouling happened. Ozonation treatment reached a chemical Oxygen Demand (COD) removal of 99.9% and caused better effluent quality. The MBR-ozonation process could achieve an acetaminophen and fluoxetine removal of around 98.4 and 57.83%, respectively. [ABSTRACT FROM AUTHOR]

Bubble size distribution was modelled by employing the population balance equation (PBE). All three bubble coalescence mechanisms (turbulence, buoyancy and laminar shear) and the main bubble breakup mechanism (breakup due to turbulent eddies) were considered in the model. Local bubble size distributions at the top and bottom of the column were obtained by solving this PBE. The results were compared with the experimental data for seven independent multiphase systems (water/air, isomax diesel/air, kerosene/air and four other liquid mixture/air) at two diverse gas velocities. The experimental adjustable constant in the coalescence efficiency function was determined by fitting the population balance to the experimental bubble size distributions. An empirical correlation was proposed for the coalescence efficiency by the dimensional analysis, which includes Reynolds and Weber numbers. © 2011 Canadian Society for Chemical Engineering [ABSTRACT FROM AUTHOR]

ABSTRACT In the present study, bubble size distribution (BSD) within a bubble column reactor was modeled using an artificial neural network (ANN). The fluids tested in the bubble column consisted of 11 different oil mixtures, each containing two different oils. Pure water was also tested. BSD was determined for various superficial gas velocities by photographing the state of the fluid. It was found that bubble size as well as distribution depended on parameters, such as gas flow rate, liquid properties, sparger pore diameter and distance from the sparger in the column. The proposed ANN model is based on more than 4500 data points collected for BSD estimation. Through statistical testing, it was found that the model has a correlation coefficient greater than 70% and upon experimental testing was found to better predict BSD than currently used correlations found in the literature. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of salt concentration on performance of a membrane bioreactor (MBR) for treating an olefin plant wastewater. For this purpose, a lab-scale submerged MBR with a flat-sheet ultrafiltration membrane was used for treatment of synthetic wastewater according to oxidation and neutralization unit of olefin plant. The synthetic wastewater was adjusted to have 500 mg/L chemical oxygen demand (COD). Trials on different concentrations of sodium sulfate (Na2SO4) (0-20 000 ppm) in the feed were conducted under aerobic conditions in the MBR. The results showed that increasing the salt concentrations causes an increase in the effluent COD, phenol, and oil concentrations. These results are due to reduction of the membrane filtration efficiency and also decline in the microbial activity that it is indicated by decreasing the sOUR in MBR. But in all the trials, the effluent COD and oil concentration was well within the local discharge limit of 100 and 10 mg/L, respectively. These results indicate that the MBR system is highly efficient for treating the olefin plant wastewater, and although high salt concentrations decreased organic contaminant removal rates in the MBR, the effluent still met the discharge limits for treating the olefin plant wastewater. [ABSTRACT FROM AUTHOR]

Investigates the effects of design and operating parameters on the hydrodynamics and oxygen transfer characteristics of draft-tube airlift biorectors. Physicochemical properties of the fermentation broths used in petroleum biodesulfurization processes; Increase in draft-tube surface area; Local gas holdups, liquid velocity, mixing time and overall volumetric oxygen transfer coefficient.