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ESRD patients suffer from side effects of the dialysis process. Comprehension of different operational parameters' effect on the hemocompatibility profiles of the separative membranes, i.e. dialyzers, could result in designing more compatible materials. This study includes a computational approach to assess the effect of pH by assessing different uremic metabolites' behavior. The pH effect was assessed by comparing the water interaction ability of different uremic metabolites (which appear at different bloodstream pH levels) using molecular dynamics (MD) simulations. Based on the findings of the studies, a new class of zwitterionic materials is introduced. The proposed modification, containing guanidine (GNDM) was experimentally implemented on poly ether sulfone (PES) membranes. Aminolysis and sultone-ring opening reactions were used to immobilize the zwitterionic structure. Attuned total reflectance-Furrier transmission infrared spectroscopy (ATR-FTIR) was used to characterize the functional groups of the modified membrane. Gravimetry was used to measure the amount of modification layer added to the membrane as well as the equilibrium water content (EWC). Atomic force microscopy (AFM) was used to measure the roughness patterns of the neat and modified membranes. Zeta potential analyzer was used to check the trend of surface charge variations. Differential scanning calorimetry (DSC) was used to assess the stable water content of the membranes. A filtration test was performed to check the stability of the immobilized materials on the membranes. The newly modified PES membranes were nearly 50 % smoother and negatively charged. DSC reflects a 16 % higher content of stable water for the modified membranes. Computational assessments also reflected that the modified structure created more hydrogen bonds and could keep the water molecules more stable on the surface of the membrane. As the new membrane owned a higher capability to keep the water more stable on its surface, it could be a perfect candidate for a hemocompatible dialysis membrane. [Display omitted] • A uremic metabolite-attached zwitterionic dialysis membrane was fabricated. • The stability of the hydration layer on the modified membranes was measured. • Standard membrane characterizations were performed to confirm the structure. • The behavior of the water molecules on the modified membrane was assessed computationally. • The durability of the modification layer was assessed using filtration and ATR-FTIR-assisted functional group tracking. [ABSTRACT FROM AUTHOR]

Abstract Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations (pesticides, herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their sources. It is followed by a discussion of Saskatchewan's groundwater status and various issues. Furthermore, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

There are abundant renewable energy sources in Iran such as wind, solar, geothermal, biomass. However, Iran is fully dependent on fossil fuels for industrial, residential and transportation sectors. It results in the country to be in top 10 producers of greenhouse gases (GHGs) into the atmosphere. GHGs can be controlled by incorporating renewable sources to produce energy. Therefore, renewable energy resources are becoming more attractive to develop sustainable energy development in Iran. However, the transformation from traditional fossil fuel infrastructures to advanced renewable technologies needs many considerations, such as strategic and core planning. In this regard, this paper covers the current state of Iran's energy market focusing on both fossil fuels and renewable energy resources. A general review is offered over the renewable energy production status in Iran and the production potentials. Finally, in conclusion, a comparisons are made over the current state, plans and also potential opportunities of Iran over each sort of energy production. [ABSTRACT FROM AUTHOR]

Abstract: Antibacterial polysulfone ultrafiltration membranes were fabricated using different silver nanoparticles in the casting solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle and dead end filtration experiment were carried out to characterize the morphology and performance of the prepared membranes while inhibition zone and filtration of bacterial suspension were used to investigate the antibacterial behavior of the membranes. Sliver release was measured in order to investigate the kinetic of silver leaching from the membranes. Less crystalline structure was obtained for membrane with smaller silver nanoparticles as confirmed by the XRD patterns. In addition, SEM studies also showed that surface pores size was reduced by adding silver nanoparticle in the casting solution. Cross section of membranes were totally affected by the addition of silver nanoparticles so that tighter finger-like structure appeared by adding 70nm silver nanoparticles. As shown in SEM images, a dense cross section was formed by addition of 2wt.% silver nanoparticles with size of 30nm in the casting solution. Surface roughness parameters obtained from AFM images showed that the silver nanoparticles with size of 70nm caused rougher surface for membrane. However, the silver nanoparticles with the size of 30nm resulted in formation of membranes with smoother surfaces. Contact angle measurement also proved more hydrophilic surface for silver modified membranes. Inhibition zone and bacterial filtration showed higher antibacteriality for membranes with smaller silver nanoparticles. [Copyright &y& Elsevier]

Computational frameworks have been under specific attention within the last two decades. Molecular Dynamics (MD) simulations, identical to the other computational approaches, try to address the unknown question, lighten the dark areas of unanswered questions, to achieve probable explanations and solutions. Owing to their complex microporous structure on one side and the intricate biochemical nature of various materials used in the structure, separative membrane materials possess peculiar degrees of complications. More notably, as nanocomposite materials are often integrated into separative membranes, thin-film nanocomposites and porous separative nanocomposite materials could possess an additional level of complexity with regard to the nanoscale interactions brought to the structure. This critical review intends to cover the recent methods used to assess membranes and membrane materials. Incorporation of MD in membrane technology-related fields such as desalination, fuel cell-based energy production, blood purification through hemodialysis, etc., were briefly covered. Accordingly, this review could be used to understand the current extent of MD applications for separative membranes. The review could also be used as a guideline to use the proper MD implementation within the related fields. [Display omitted] • Overview of molecular dynamics simulation for membrane separation and porous materials. • MD-driven Initial Parameters. • Contribution of Computational Tools to Different Membrane Technology Subsections. • Instances of MD Applications for Characterization Membrane Materials. [ABSTRACT FROM AUTHOR]

Abstract: In this research, the surface of poly (vinylidene fluoride) (PVDF)/sulfonated polyethersulfone (SPES) blend membrane prepared via immersion precipitation was modified by depositing of TiO2 nano-particles followed by UV irradiation to activate their photocatalytic property. The membranes were characterized by FTIR, SEM, AFM, contact angle, dead end filtration (pure water flux and BSA solution flux), antifouling analysis and antibacterial activity. The FTIR spectrum confirmed the presence of OH functional groups on the PVDF/SPES membrane structure, which was the key factor for deposition, and self-assembly of TiO2 nanoparticles on the membrane surface. The SEM and AFM images indicated that the TiO2 nanoparticles were deposited on the PVDF/SPES membrane. The contact angle measurements showed that the hydrophilicity of PVDF/SPES membrane was strongly improved by TiO2 deposition and UV irradiation. The filtration results indicated that the initial flux of TiO2 deposited PVDF/SPES membranes was lower than the initial flux of neat PVDF/SPES membrane. However, the former membranes showed lower flux decline compared to the neat PVDF/SPES membrane. The BSA rejection of modified membranes was improved. The fouling analysis demonstrated that the TiO2 deposited PVDF/SPES membranes showed the fewer tendencies to fouling. The results of antibacterial study showed that the UV irradiated TiO2 deposited PVDF/SPES membranes possess high antibacterial property. [Copyright &y& Elsevier]

• Transesterification reactors for biodiesel production are comprehensively reviewed. • The effects of the main parameters on the transesterification process are scrutinized. • Pros and cons of each reactor technology for biodiesel production are outlined. • The sustainability aspects of biodiesel production are comprehensively discussed. • Policy and economic aspects of biodiesel have been extensively securitized. Diesel engines are preferred over spark ignition counterparts for heavy-duty applications and power generation plants because of their higher efficiency, durability, and productivity. Currently, the research interests have been propelled towards renewable and sustainable diesel fuels such as biodiesel in order to address the environmental and energy security challenges associated with these energy systems. However, the most challenging issue concerning large-scale production of biodiesel is its relatively high cost over fossil-based diesel owing to high feedstock and manufacturing costs. Therefore, cost-effective and eco-friendly biodiesel production technologies should be necessarily developed and continuously improved in order to make this biofuel more competitive vs. its petroleum counterpart. Accordingly, this paper comprehensively reviews biodiesel manufacturing techniques from natural oils and fats using conventional and advanced technologies with an in-depth state-of-the-art focus on the utmost important unit, i.e., transesterification reactor. The effects of the main influential parameters on the transesterification process are first discussed in detail in order to better understand the mechanisms behind each reactor technology. Different transesterification reactors; e.g. , tubular/plug-flow reactors, rotating reactors, simultaneous reaction-separation reactors, cavitational reactors, and microwave reactors are then scrutinized from the scientific and practical viewpoints. Merits and limitations of each reactor technology for biodiesel production are highlighted to guide future R&D on this topic. At the end of the paper, the sustainability aspects of biodiesel production are comprehensively discussed by emphasizing on the biorefinery concept utilizing waste-oriented oils. [ABSTRACT FROM AUTHOR]

Amine functionalized Multi-walled carbon nanotubes (F-MWCNTs)/polyethersulfone (PES) membranes were prepared using phase inversion induced by immersion precipitation. Crude MWCNTs were chemically treated using strong acids (H2SO4/HNO3) and 1,3-phenylenediamine (mPDA) to produce the functional amine groups (NH2) on their surfaces. F-MWCNTs with different concentration were blended in the casting solution containing PES, polyvinylpyrrolidone (PVP) and dimethylacetamide (DMAC). Pure water was used as non-solvent. The FTIR spectra indicated that the amine functional groups were produced on the surface of MWCNTs. The membranes prepared with different concentrations of F-MWCNTs were characterized using contact angle, field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and permeation tests. The surface hydrophilicity of membranes was significantly improved by addition of F-MWCNTs in the casting solution. An increment in the porosity, pore size and surface roughness of the membranes was observed by increasing F-MWCNTs content up to 1 wt.%. Further addition of F-MWCNTs caused a reduction in porosity and roughness of formed membrane. The membranes prepared with 0.5 and 1 wt.% of F-MWCNTs showed higher performance than neat membrane. Addition of F-MWCNTs in the casting solution improved the BSA rejection and antifouling properties of PES membrane. [ABSTRACT FROM AUTHOR]

Forward osmosis (FO) is an osmotically driven process widely studied for water desalination, wastewater treatment, and water reuse, as well as dilution and concentration of aqueous streams. However, its application is still hampered by the lack of ideal draw solutes, high-performance membranes, and fouling/biofouling. Biofouling is particularly challenging when FO is applied for seawater desalination and wastewater treatment. Over the last decade, many attempts have been made to exploit advances in materials science to obtain membranes with anti-biofouling properties to prevent or to reduce the detrimental effects of this phenomenon. In this review, we address the various approaches of membrane surface functionalization for biofouling control and mitigation. Recent developments in surface modification of thin-film composite and asymmetric membranes using surface coating, surface functionalization, and incorporation of tailored materials for biofouling control in FO are critically discussed. The future perspectives of anti-biofouling materials and FO membranes are reviewed to shed light on the future research directions for developing the true potential surface modification approach for the FO process. • Mechanism of biofouling in FO membranes and the current control strategies are presented. • Recent advances in the science of materials and their exploitation in engineering FO are discussed. • Methods for functionalization of FO membranes to mitigate the biofouling are reviewed. • Directions for future research in functionalized FO membrane development to biofouling control are proposed. [ABSTRACT FROM AUTHOR]