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To address the issue of low mechanical strength in self-supported hollow fiber membranes, a research study was conducted to fabricate polysulfone braid-reinforced hollow fiber (PSF BRHF) membranes for natural gas purification. In this study, polyethylene (PET) was used as a braid support. PSF BRHF membranes were fabricated by employing dip coating and drying technique. The BRHF membranes underwent comprehensive analysis, including the manipulation of polymer (PSF) concentration (15 wt%, 18 wt%, and 21 wt%) and the number of coating layers (1–4). Characterization of the fabricated membrane samples involved scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gas separation performance testing, and mechanical strength testing. The results indicated that membranes fabricated with higher polymer concentrations exhibited a denser structure with a thicker separation layer. An increase in the separation layer thickness was also observed with an increasing number of coating layers. Importantly, all fabricated membrane samples demonstrated remarkable thermal stability. To assess the performance, gas separation tests were conducted using pure gases at 3 bar. Notably, the membrane sample with 21 wt% PSF and the 3rd coating layer (21_3 PSF) exhibited the most promising gas separation performance among all the samples selected to carry out the separation performance test, achieving a CO2/CH4 selectivity of 1.83. Mechanical strength testing revealed that 21_3 PSF BRHF (68.2 MPa) fabricated in this study outperformed conventional self-supported PSF hollow fiber membranes (9.44 MPa), as reported in the literature. These findings underscore the potential of BRHF membranes for natural gas purification, although further improvements are still possible. [ABSTRACT FROM AUTHOR]

• ZIF-8 nanofillers as potent carbon dioxide adsorption for natural gas purification. • Development and analysis of ZIF-8 based membrane with different ZIF-8 loadings. • Excellent separation and durability of ZIF-8 based membrane for gas purification. • Permeance and ideal selectivity of ZIF-8 membrane increased by 72.5 % and 1196.2 % To prevent pipe damage and lower operating costs, natural gas must be cleaned of pollutants like carbon dioxide (CO 2) and hydrogen sulphide (H 2 S). High selectivity of the functional material in the mixed matrix membranes (MMMs) allows for a more efficient gas separation compared to traditional polymeric membranes. However, poor dispersion and compatibility between the functional material and the polymer matrix become one of the major problems of MMMs. The use of zeolite imidazole (ZIF-8) in MMMs has been explored for its ability to separate CO 2 /CH 4 due to its versatile gas molecule diameter range and effective CO 2 adsorption. In this study, the effects of ZIF-8 at various loadings were examined on the physical and chemical properties of dual layer hollow fiber MMMs and gas separation efficiency. Following the successful production of 86.25 nm ZIF-8 nanoparticles, ZIF-8-based DLHF MMMs were created. The results showed that 0.5 wt% ZIF-8 loading provided the best results, with excellent interaction between the polymer PSf and the inorganic filler ZIF-8, strong heat resistance, and chemical stability. Increased CO 2 permeability and CO 2 /CH 4 ideal selectivity by 72.5 % and 1196.2 % respectively, compared to the unmodified membrane. It was inferred through this study that minimal loading of 0.5 wt% ZIF-8 in the DLHF MMMs improved their ability to separate gases, making them a good option for capturing CO 2. [ABSTRACT FROM AUTHOR]

This study aimed to examine the impact of BPA exposure on pregnancy and foetuses on cardiac tissues and the expression of cardiac microRNAs (miRNAs) related to heart development and diseases. Pregnancy is known to be the "critical windows" in determining the offspring physical and cells development in their life after birth. The increment of the risk of cardiovascular disease (CVD) in a later stage of life has been reported by few studies demonstrated from prenatal exposure of BPA. BPA has been shown to alter miRNAs expression profiles for organ development, regeneration and metabolic functions. These alterations have been associated with the risk of CVDs. However, the associations between pregnancy outcomes and miRNAs expression in cardiac of mother- and foetuses-exposed to BPA are still not entirely explored. In BPA-exposed pregnant rat groups, a significant weight gained was observed in comparison to control (p < 0.05). Interestingly, significant changes in systolic and diastolic blood pressure between the first and third trimester of BPA-exposed pregnant rats were also observed (p < 0.05). In BPA-exposed pregnant rats, miR-499-5p was significantly altered in the heart (p < 0.01). Meanwhile, altered miR-17-5p, -208-3p, and -210-3p expressions were observed in all heart of the foetuses from BPA-exposed pregnant rats (p < 0.05). In H&E staining, BPA-exposed foetal hearts showed a sign of fibrosis while BPA-exposed pregnant rats showed muscle remnant. Masson trichrome staining further confirmed the presence of fibrosis observed in BPA-exposed foetal heart and reduced expression of cardiac troponin I (cTnI) was also observed in BPA-exposed foetal heart. In summary, altered cardiac miRNAs with histological changes were observed in both mother- and foetus-exposed BPA These findings put forward the importance of future work to further understand how prenatal BPA exposure affect foetuses in their later stage of life. [ABSTRACT FROM AUTHOR]

The inability of most photocatalysts to continue the catalytic process after the removal of light irradiation is one of their major drawbacks. In this work, a ternary nanocomposite of titanium oxide (TiO 2) supported with tungsten oxide (WO 3) and hybridized with graphene oxide (GO) (TiO 2 -WO 3 @GO) photocatalyst with electron energy storage properties was synthesized for oilfield-produced water (OPW) treatment under visible light and in dark conditions. WO 3 addition extended the light absorption range of TiO 2 into the visible light while also serving as an electron storage material for dark catalysis (memory catalysis). The GO serves as an efficient electron acceptor and transporter to prevent charge carrier recombination, thereby enhancing interfacial electron transfer within the photocatalyst system. 2.5 wt%, 5 wt%, and 10 wt% of WO 3 precursors were reacted with TiO 2 precursor and GO was further added to synthesize the nanocomposites via a modified sol-gel and solution-based approach for the first time. The properties of the nanocomposite were assessed using a wide range of characterization. The nanocomposite containing 5 wt% WO 3 showed the best photocatalytic activity with the total organic content (TOC) degradation of 27.7% within 4 h of photodegradation in visible light, which is better than 22 % in 5 h under UV light so far reported in the literature. The nanocomposite also exhibited electron energy storage properties for dark catalysis after pre-illumination, i.e., 16.6% TOC degradation in 3 h in dark conditions. This low % TOC degradation in the dark could be attributed to the complex nature of OPW. This work has further confirmed the possibility of the use of photocatalysts for dark catalysis. [ABSTRACT FROM AUTHOR]

A significant drawback of the traditional photocatalysts such as titanium dioxide (TiO 2) is their inability to absorb visible light from the solar spectrum due to their wide band gap energy. They are only photoactive in the ultraviolet (UV) region which is just a little fraction of the solar spectrum and could be harmful with much exposure to it. Due to its abundance in the solar spectrum, visible light needs to be harnessed for environmental applications. However, we lack visible light driven photocatalysts with long-lasting energy storage capacity for "round-the-clock photocatalytic" (RTCP) applications. For this reason, there is a growing need to find new photocatalysts that can mitigate these bottlenecks. It is evident from some carefully selected published articles (1976–2021) that tungsten oxide (WO 3) and its composites have attracted popularity in recent years because of its outstanding properties and particularly its smaller band gap energy of 2.8 eV. However, pristine WO 3 is limited due to relatively low energy density and smaller specific surface area. These drawbacks can be addressed by developing various WO 3 – based materials to improve their performance. This paper reviews and discusses their recent development in surface advancement, morphology control, modification of nanostructured WO 3 and its composites, and their RTCP energy storage for photocatalytic activities in visible light and the dark for environmental applications. Specific aspects focused on its nature, structure, properties, synthesis, coatings, deposition, approaches at modifying and enhancing its visible light photoactivity for enhanced performance and energy storage potential. [Display omitted] • Synthesis techniques for WO 3 -based photocatalysts are discussed. • Visible light enhancement strategies for WO 3 -based photocatalysts are elaborated. • WO 3 "round the clock photocatalysis" is described. • WO 3 - based photocatalytic memory for environmental applications is reviewed. • WO 3 -based catalysts are promising for continuous day and night photocatalysis. [ABSTRACT FROM AUTHOR]

The presence of bisphenol A (BPA) in various water sources has potentially led to numerous adverse effects in human such as increased in blood pressure and derangement in liver function. Thus, a reliable treatment for the removing BPA is highly required. This present work aimed to study the efficiency of visible light driven photocatalytic dual-layer hollow fiber (DLHF) membrane for the removal of BPA from water and further investigated its detrimental effects by using an in-vivo model. The prepared membranes were characterized for their morphology, particles distribution, surface roughness, crystallinity and light absorption spectra. The removal of 81.6% and 86.7% in BPA concentration was achieved for N-doped TiO2 DLHF after 360 min of visible and UV light irradiation, respectively. No significant changes for all three groups were observed in liver function test meanwhile the rats-exposed to untreated BPA water shows significance blood pressure increment contrary to rats-exposed to treated BPA water. Similarly, the normal morphology in both jejunum and ileum were altered in rats-exposed to untreated BPA water group. Altogether, the presence of N-doped TiO2 in DLHF are shown to significantly enhance the photocatalytic degradation activity under visible irradiation, which effectively mitigates the effect of BPA in an in-vivo model. [ABSTRACT FROM AUTHOR]

This present study aims to develop a visible-light driven photocatalytic dual layer hollow fiber (DLHF) membrane for photodegradation activity. Nitrogen-doped TiO 2 DLHF membranes with different loadings of N-doped TiO 2 were successfully fabricated via a single step co-extrusion method. The fabricated membranes were characterized for their morphology and properties. The incorporation of N-doped TiO 2 into membrane matrix has shifted the absorption capability into visible light region with lowest band gap energy obtained was 2.63eV. The photocatalytic performance evaluations of the N-doped TiO 2 DLHF reported 75% and 100% of Reactive Black 5 (RB5) removal were achieved after 360 min of visible and UV light illumination respectively. Altogether, N-doped TiO 2 DLHF exhibits excellent photocatalytic degradation activity under visible and UV light irradiation, hence have a promising potential in removing RB5 and other organic contaminants for water treatment. • The fabrication of visible light driven photocatalytic dual layer hollow fiber via co-extrusion technique. • The incorporation of N-doped TiO 2 into membrane surface successfully expand the photoresponse into the visible light region. • Good photocatalytic activity with 75% and 100% removal of RB5 under visible and UV light irradiation, respectively. • Efficient photocatalytic degradation process of visible-light driven N-doped TiO 2 for contaminants present in the water. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 -WO 3 @GO/PVDF-DLHF photocatalytic membrane with catalytic memory was fabricated. • 3 wt% photocatalyst loaded membrane achieved 98.62% TOC rejection in visible light. • Good anti-fouling and self-cleaning with water flux of 99.51 L/m2h and FRR of 91.35 % • 3 wt% loaded membrane achieved 68.56% TOC rejection for memory catalysis. • Excellent stability after prolonged use with a TOC rejection of 89.76% Oilfield-produced water (OPW) is a complex wastewater that is difficult to treat causing significant harm to the environment. Photocatalytic membranes are emerging for OPW treatment. However, they suffer significant fouling due to the inability to self-clean during prolonged treatment. They also require continuous photo assistance to sustain the catalytic process. This limits their applications in the absence of light referred to as memory catalysis. This work reported the fabrication of a unique ternary photocatalyst TiO 2 -WO 3 @GO/PVDF dual-layer hollow fiber (DLHF) photocatalytic membranes for photodegradation and memory catalysis of total organic carbon (TOC) in OPW. The photocatalytic membranes were fabricated via phase inversion and co-extrusion method varying (0,1,3,5) wt% of the TiO 2 -WO 3 @GO photocatalyst. The membranes were characterized and their performances for TOC removal under visible light and memory catalysis were evaluated. The membranes exhibited excellent TOC degradation, rejection, anti-fouling, self-cleaning, and catalytic memory. The WO 3 was responsible for electron storage within the system and improved the absorptive capacity of TiO 2 in the visible range while the GO promoted the electron-hole transfer creating abundant active sites for photocatalytic reaction. The 3 wt% loaded membrane showed the best TOC rejection of 98.62 % after 6 h of operation, water and permeate fluxes of 99.51 L/m2h, and 76.54 L/m2h respectively. The membrane showed good catalytic memory in the dark with a TOC rejection of 68.56 % after 6 h, OPW flux recovery ratio (FRR), and TOC rejection of 91.35 % and 89.76 % respectively after 5 cycles of operation under visible light. This work is expected to bring a paradigm shift toward the fabrication of memory catalytic membranes for wastewater treatment. [ABSTRACT FROM AUTHOR]

Previous water treatments used are nondestructive and lead to the formation of new type of pollution. Photocatalytic reaction which induced by illumination of semiconductors in suspension was one of the most promising processes for wastewater treatment due to the ability of providing an interface with the aqueous medium and induce an advanced oxidation process. In this study, Malaysian bauxite has been selected as a new potential candidate for photocatalytic degradation. Bauxite powder was undergone heat treatment ranging from 800 to 1000 °C and then was characterized by field emission scanning electron microscope, X-ray diffraction (XRD), Brunauer–Emmett–Teller, ultraviolet–visible–near infrared spectroscopy and suspension absorbance test to determine the existing components and their composition, structure of the powder, band gap energy as well as the photocatalytic efficiency of bauxite in suspension of various concentrations of Reactive Black 5 (RB5) ranging from 5 to 20 ppm. The finding revealed that bauxite possessed slight changes in terms of XRF composition as well as particle size due to thermal process. This is supported by XRD analysis which showed that phase conversion occurred at 800 °C. Heat-treated bauxite possesses low band gap energy (2.04 eV). The photocatalytic activity of raw bauxite suspension was measured after 360 min illumination, and it proved that there was degradation of 67% and 63% from the initial 5 ppm concentration of RB5 using visible and UV lights, respectively. This finding clearly shows that bauxite exhibits good photocatalytic degradation and hence has a promising potential in removing dyes for industrial wastewater. [ABSTRACT FROM AUTHOR]

Oilfield-produced water (OPW) contains a complex mixture of toxic and hazardous organic and inorganic compounds. Refractory polycyclic aromatic hydrocarbons (PAHs) and polyaromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene (BTEX) chemical compounds present in OPW which result from hydrocarbon sources and chemicals added during the oil recovery process, have become a source of global concern. Their continuous presence in the OPW requires suitable technology to remove them before their discharge to the environment. When the OPW contains harmful pollutants combined with oil in minute size, the treatment performance of various water technologies appears insufficient due to the generation of secondary by-products, which are also recalcitrant and toxic. To consolidate scattered knowledge of OPW in the field of water pollution control, this article critically reviews and evaluates the technical feasibility of heterogeneous photocatalysis for OPW treatment, their bottlenecks in applications, and the way forward for the removal of recalcitrant hydrocarbon compounds from OPW. This work also presents the nature, composition, and health implications of these compounds in the OPW. Pertinent factors for effective photodegradation were presented. It also critically evaluates and discusses a variety of pilot and commercial-scale applications of photocatalysis in water treatment and its limitations. It was conclusively evident from 239 published articles (1988–2022) that heterogeneous photocatalytic degradation is a powerful approach for the removal of the hydrocarbon compounds such as PAHs, BTEX, and phenol with an average of over 80% of degradation efficiency. The photocatalytic process can be scaled up to the commercial scale with the proper design of photocatalytic reactors and the synthesis of advanced photocatalysts. [Display omitted] • Organic hydrocarbons in produced water have a detrimental effect on the environment. • Photocatalysis can efficiently remove recalcitrant hydrocarbons from produced water. • Toxicity/environmental hazards from photocatalytic nanomaterials need further study. • Large surface area and efficient light absorption are ideal for photocatalyst design. • Large-scale photocatalysis applications require advanced reactor and catalyst design. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) that can cause adverse effects on human health. The incorporation of materials as visible light photocatalysts and its energy storage capability allow for the photodegradation of BPA, especially in the absence of a light source. To date, there have been no significant studies regarding energy storage in membrane technology, with only a focus on the suspension form. Hence, this study was conducted to degrade the pollutant through a co-extrusion process using a mixture of copper (II) oxide and tungsten oxide as the photocatalyst and energy storage materials, respectively. Both materials were embedded into polyvinylidene (PVDF) membranes to produce a Cu2O/WO3/PVDF dual-layer hollow fiber (DLHF) membrane. The outer dope extrusion flow rate was set at 3 mL/min, 6 mL/min, and 9 mL/min with photocatalyst:polymer ratios of 0.3, 0.50, and 0.7 Cu2O/WO3/PVDF, respectively. The performance of the membranes for each ratio was evaluated using 2 ppm of BPA with visible light irradiation. The results showed that each membrane's outer and inner layers featured finger-like void structures, while the intermediate part had a sponge-like structure. The membrane with the photocatalyst:polymer ratio of 0.5 was hydrophilic and had a high porosity of 54.97%, resulting in a high flow of 510 L/m2h. Under visible light irradiation, a 0.5 Cu2O/PVDF DLHF membrane with a 6-mL/min outer dope flow rate was able to remove 97.82% of 2-ppm BPA without copper leaching into the water sample. Under dark conditions, the DLHF sample showed the capability of energy storage performance and could drive certain degradation after lighting off up to 70.73% of 2-ppm BPA. The photocatalytic DLHF membrane with the ratio of 0.5 was the most optimal due to its potential morphology and ability to degrade a large amount of BPA. It is important to emphasize that usage of materials with the capability for energy storage can provide a significant contribution toward more practical membranes, so photodegradation can occur even in dark conditions. [ABSTRACT FROM AUTHOR]

Oilfield produced water (OPW) is one of the most important by-products, resulting from oil and gas exploration. The water contains a complex mixture of organic and inorganic compounds such as grease, dissolved salt, heavy metals as well as dissolved and dispersed oils, which can be toxic to the environment and public health. This article critically reviews the complex properties of OPW and various technologies for its treatment. They include the physico-chemical treatment process, biological treatment process, and physical treatment process. Their technological strengths and bottlenecks as well as strategies to mitigate their bottlenecks are elaborated. A particular focus is placed on membrane technologies. Finally, further research direction, challenges, and perspectives of treatment technologies for OPW are discussed. It is conclusively evident from 262 published studies (1965–2021) that no single treatment method is highly effective for OPW treatment as a stand-alone process however, conventional membrane-based technologies are frequently used for the treatment of OPW with the ultrafiltration (UF) process being the most used for oil rejection form OPW and oily waste water. After membrane treatment, treated effluents of the OPW could be reused for irrigation, habitant and wildlife watering, microalgae production, and livestock watering. Overall, this implies that target pollutants in the OPW samples could be removed efficiently for subsequent use, despite its complex properties. In general, it is however important to note that feed quality, desired quality of effluent, cost-effectiveness, simplicity of process are key determinants in choosing the most suitable treatment process for OPW treatment. [Display omitted] • Oilfield produced water (OPW) poses a potential danger to the environment. • Membrane-based technologies are gaining acceptance for OPW treatment. • OPW management is based on fundamental laws, regulations, and standards. • Treated OPW effluent has the potential for beneficial reuse. • AOP coupled with Membrane technology can be most effective in OPW treatment. [ABSTRACT FROM AUTHOR]

Among wide range of membrane-based operations, membrane contactors, as they reify comparatively modern membrane-based mechanism are gaining quite an attention in both pilot and industrial scales. In recent literature, carbon capture is one of the most researched applications of membrane contactors. Membrane contactors have the potential to minimize the energy consumption and capital cost of traditional CO 2 absorptions columns. In a membrane contactor, CO 2 regeneration can take place below the solvent boiling point, resulting into lower consumption of energy. Various polymeric as well as ceramic membrane materials have been employed in gas liquid membrane contactors along with several solvents including amino acids, ammonia, amines etc. This review article provides detailed introduction of membrane contactors in terms of CO 2 removal. It also discusses that the main challenge that is faced by membrane contactors is membrane pore wetting caused by solvent that in turn can reduce the mass transfer coefficient. Other potential challenges such as selection of suitable solvent and membrane pair as well as fouling are also discussed in this review and are followed by potential ways to reduce them. Furthermore, both membrane gas separation and membrane contactor technologies are analysed and compared in this study on the basis of their characteristics, CO 2 separation performances and techno economical transvaluation. Consequently, this review provides an opportunity to thoroughly understand the working principle of membrane contactors along its comparison with membrane-based gas separation technology. It also provides a clear understanding of latest innovations in membrane contactor module designs as well as challenges encountered by membrane contactors along with possible solutions to overcome these challenges. Finally, semi commercial and commercial implementation of membrane contactors has been highlighted. [Display omitted] • Comprehensive review of membrane contactors for CO 2 separation. • Review for conventional membrane gas separation technology and membrane contactors. • Latest innovations in membrane contactor module designs. • Challenges encountered by membrane contactors for CO 2 separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly efficient bi-metallic MOF adsorbent with a large surface area was synthesized. • Only up to 2 mol % of Cu metal can be successfully substituted with Mg metal in MOF-199. • Polyethyleneimine (PEI) was incorporated into bi-metallic MOF to alter its pore size and environment. • The bi-metallic MOF composite loaded with 40 wt% PEI showed highest CO 2 /N 2 adsorption selectivity. The fine-tuning of metal–organic frameworks (MOFs) can enable the development of effective adsorbents for the selective capture of less polarizable carbon dioxide (CO 2) from flue gases. In this work, a series of bi-metallic MOFs with different Mg metal concentrations (1–10 mol%) were synthesized by in situ metal substitution followed by post-synthetic functionalization with 10–50 wt% of polyethyleneimine (PEI). Detailed characterization confirmed the successful incorporation of the secondary metal and amine group into the MOF framework. Results showed that only up to 2 mol% of copper (Cu) can be substituted by Mg metal in the framework of MOF-199; further increase in Mg content disrupts the electrostatic equilibrium, leading to the formation of carbon matter-based copper nanoparticles instead. The sorption results indicated that 2 mol% Mg-doped MOF (MOF@Mg2) demonstrate a CO 2 uptake of 8.61 (mmol/g) at 1 bar and 273.15 K. This reflects a 17.78 % increase in CO 2 absorption capacity compared to the pristine MOF. Furthermore, 40 wt% PEI-loaded MOF exhibited a 37.90 % enhancement in CO 2 adsorption selectivity. This study explores in detail the intricate process of optimizing the metal ratio and PEI loading in the bimetallic MOF-199(Cu, Mg), aiming to improve its CO 2 adsorption efficiency. [ABSTRACT FROM AUTHOR]

Existing toxic solvents in the manufacturing of polymeric membranes have been raising concerns due to the risks of exposure to health and the environment. Furthermore, the lower tensile strength of the membrane renders these membranes unable to endure greater pressure during water treatment. To sustain a healthier ecosystem, fabrication of polyvinylidene fluoride (PVDF) hollow fiber membrane using a less toxic solvent, triethyl phosphate (TEP), with a lower molecular weight polyethylene glycol (PEG 400) (0–3 wt.%) additive were experimentally demonstrated via a phase inversion-based spinning technique at various air gap (10, 20 and 30 cm). Membrane with 2 wt.% of PEG 400 exhibited the desired ultrafiltration asymmetric morphology, while 3 wt.% PEG 400 resulting microfiltration. The surface roughness, porosity, and water flux performance increased as the loading of PEG 400 increased. The mechanical properties and contact angle of the fabricated membrane were influenced by the air gap where 20 cm indicate 2.91 MPa and 84.72°, respectively, leading to a stronger tensile and hydrophilicity surface. Lower toxicity TEP as a solvent helped in increasing the tensile properties of the membrane as well as producing an eco-friendly membrane towards creating a sustainable environment. The comprehensive investigation in this study may present a novel composition for the robust structure of polymeric hollow fiber membrane that is suitable in membrane technology. [ABSTRACT FROM AUTHOR]