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1.
Chem Rec ; 24(6): e202400043, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38874111

RESUMO

Functionalized nanoporous heteropoly acids (HPAs) have garnered significant attention in recent years due to their enhanced surface area and porosity, as well as their potential for low-cost regeneration compared to bulk materials. This review aims to provide an overview of the recent advancements in the synthesis and applications of functionalized HPAs. We begin by introducing the fundamental properties of HPAs and their unique structure, followed by a comprehensive overview of the various approaches employed for the synthesis of functionalized HPAs, including salts, anchoring onto supports, and implementing mesoporous silica sieves. The potential applications of functionalized HPAs in various fields are also discussed, highlighting their boosted performance in a wide range of applications. Finally, we address the current challenges and present future prospects in the development of functionalized HPAs, particularly in the context of mesoporous HPAs. This review aims to provide a comprehensive summary of the recent progress in the field, highlighting the significant advancements made in the synthesis and applications of functionalized HPAs.

2.
Sep Purif Technol ; 286: 120454, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35035270

RESUMO

Consumption of pathogenic contaminated water has claimed the lives of many people. Hence, this scenario has emphasized the urgent need for research methods to avoid, treat and eliminate harmful pathogens in wastewater. Therefore, effective water treatment has become a matter of utmost importance. Membrane technology offers purer, cleaner, and pathogen-free water through the water separation method via a permeable membrane. Advanced membrane technology such as nanocomposite membrane, membrane distillation, membrane bioreactor, and photocatalytic membrane reactor can offer synergistic effects in removing pathogen through the integration of additional functionality and filtration in a single chamber. This paper also comprehensively discussed the application, challenges, and future perspective of the advanced membrane technology as a promising alternative in battling pathogenic microbial contaminants, which will also be beneficial and valuable in managing pandemics in the future as well as protecting human health and the environment. In addition, the potential of membrane technology in battling the ongoing global pandemic of coronavirus disease 2019 (COVID-19) was also discussed briefly.

3.
J Environ Manage ; 308: 114556, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35124308

RESUMO

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.


Assuntos
Campos de Petróleo e Gás , Purificação da Água , Animais , Gado , Ultrafiltração , Águas Residuárias/análise , Purificação da Água/métodos
4.
J Environ Manage ; 290: 112565, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33873023

RESUMO

The vast amount of oily wastewater released to the environment through industrialization has worsened the water quality in recent years, posing adverse impacts on general human health. Oil emulsified in water is one of the most difficult mixtures to be treated, making it imperative for new technology to be explored to address this issue. The use of conventional water treatment such as flotation, coagulation, precipitation, adsorption, and chemical treatment have low separation efficiencies and high energy costs, and are not applicable to the separation of oil/water emulsions. Therefore, there is a demand for more efficient methods and materials for the separations of immiscible oil/water mixtures and emulsions. Superwetting materials that can repel oil, while letting water pass through have been widely explored to fit into this concern. These materials usually make use of simultaneous hydrophilic/oleophobic mechanisms to allow a solid surface to separate oily emulsion with little to no use of energy. Also, by integrating specific wettability concepts with appropriate pore scale, solid surfaces may achieve separation of multifarious oil/water mixtures namely immiscible oil/water blends and consolidated emulsions. In this review, materials used to impart superwetting in solid surfaces by focusing on superhydrophilic/superoleophobic wetting properties of the materials categorized into fluorinated and non-fluorinated surface modification are summarized. In each material, its background, mechanism, fabricating processes, and their effects on solid surface's wetting capability are elaborated in detail. The materials reviewed in this paper are mainly organic and green, suggesting the alternative material to replace the fluorine group that is widely used to achieve oleophobicity in oily wastewater treatment.


Assuntos
Óleos , Purificação da Água , Humanos , Interações Hidrofóbicas e Hidrofílicas , Águas Residuárias , Molhabilidade
5.
J Environ Manage ; 268: 110718, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32510449

RESUMO

Integrated fixed-film activated sludge (IFAS) process is considered as one of the leading-edge processes that provides a sustainable solution for wastewater treatment. IFAS was introduced as an advancement of the moving bed biofilm reactor by integrating the attached and the suspended growth systems. IFAS offers advantages over the conventional activated sludge process such as reduced footprint, enhanced nutrient removal, complete nitrification, longer solids retention time and better removal of anthropogenic composites. IFAS has been recognized as an attractive option as stated from the results of many pilot and full scales studies. Generally, IFAS achieves >90% removals for combined chemical oxygen demand and ammonia, improves sludge settling properties and enhances operational stability. Recently developed IFAS reactors incorporate frameworks for either methane production, energy generation through algae, or microbial fuel cells. This review details the recent development in IFAS with the focus on the pilot and full-scale applications. The microbial community analyses of IFAS biofilm and floc are underlined along with the special emphasis on organics and nitrogen removals, as well as the future research perspectives.


Assuntos
Esgotos , Águas Residuárias , Biofilmes , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Nitrificação , Nitrogênio
6.
Entropy (Basel) ; 22(2)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33285953

RESUMO

Flue gas contains high amount of low-grade heat and water vapor that are attractive for recovery. This study assesses performance of a hybrid of water scrubber and membrane distillation (MD) to recover both heat and water from a simulated flue gas. The former help to condense the water vapor to form a hot liquid flow which later used as the feed for the MD unit. The system simultaneously recovers water and heat through the MD permeate. Results show that the system performance is dictated by the MD performance since most heat and water can be recovered by the scrubber unit. The scrubber achieved nearly complete water and heat recovery because the flue gas flows were supersaturated with steam condensed in the water scrubber unit. The recovered water and heat in the scrubber contains in the hot liquid used as the feed for the MD unit. The MD performance is affected by both the temperature and the flow rate of the flue gas. The MD fluxes increases at higher flue gas temperatures and higher flow rates because of higher enthalpy of the flue gas inputs. The maximum obtained water and heat fluxes of 12 kg m-2 h-1 and 2505 kJm-2 h-1 respectively, obtained at flue gas temperature of 99 °C and at flow rate of 5.56 L min-1. The MD flux was also found stable over the testing period at this optimum condition. Further study on assessing a more realistic flue gas composition is required to capture complexity of the process, particularly to address the impacts of particulates and acid gases.

7.
Water Environ Res ; 90(1): 64-73, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29268840

RESUMO

This study aimed to investigate the effects of ferrihydrite (Fh) nanoparticle loading on the physicochemical properties of polysulfone (PSf) membranes fabricated via the phase inversion method. The morphologies and physicochemical properties of prepared Fh and PSf/Fh mixed matrix membranes (MMMs) were characterized using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Fourier transmission infra-red (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), pure water flux analysis, contact angle measurement, and membrane porosity analysis. FTIR study indicated that a new O-H band was formed when Fh was added into the membrane matrix. SEM analysis showed the formation of typical asymmetric membrane structures with elongated fingerlike and looser porous layers. Increasing the loading of Fh significantly enhanced membrane pure water flux from 230.2 L/m2•h (M-Fh 0%) to 726.6 L/m2•h (M-Fh 15.3%), attributed to the improved membranes structures, membranes wettability, surface roughness, and overall porosity. The findings suggest incorporation of Fh into PSf membranes improves physicochemical properties of the membranes which are applicable for water/wastewater treatment.


Assuntos
Compostos Férricos/química , Polímeros/química , Sulfonas/química , Águas Residuárias/química , Purificação da Água/instrumentação , Membranas Artificiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos
8.
J Environ Manage ; 224: 252-262, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30055458

RESUMO

Adsorption is one of the most efficient ways to remove heavy metal from wastewater. In this study, the adsorptive removal of hexavalent chromium, Cr (VI) from aqueous solution was investigated using natural zeolite, clinoptilolite, in the form of hollow fibre ceramic membrane (HFCM). The HFCM sample was prepared using phase inversion-based extrusion technique and followed by sintering process at different sintering temperatures in the range of 900-1050 °C. The fabricated HFCM was characterised using scanning electron microscopy (SEM), contact angle, water permeability, and mechanical strength for all HFCMs sintered at different temperatures. The adsorption and filtration test of Cr (VI) were performed using an in-house water permeation set up with a dead-end cross-flow permeation test. An asymmetric structure with sponge- and finger-like structures across the cross-section of HFCM was observed using SEM. Based on the characterisation data, 1050 °C was chosen to be the best sintering temperature as the water permeability and mechanical strength of this HFCM were 29.14 L/m2∙h and 50.92 MPa, respectively. The performance of the HFCM in adsorption/filtration was 44% of Cr (VI) removal at the Cr (VI) concentration of 40 mg/L and pH 4. In addition, the mathematical model was also performed in simulating the experimental data obtained from this study. All in all, the natural zeolite-based HFCM has a potential as a single-step Cr (VI) removal by membrane adsorption for the wastewater treatment.


Assuntos
Cromo/isolamento & purificação , Purificação da Água , Zeolitas , Adsorção , Cerâmica , Cromo/química , Concentração de Íons de Hidrogênio , Águas Residuárias , Poluentes Químicos da Água
9.
Bioelectrochemistry ; 160: 108770, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38943780

RESUMO

This study assessed the viability of an anion-exchange microbial fuel cell (MFC) for extracting electricity from palm oil mill effluent (POME), a major pollutant in palm-oil producing regions due to increasing demand. The MFC incorporated a tubular membrane electrode assembly (MEA) with an air core, featuring a carbon-painted carbon-cloth cathode, an anion exchange membrane (AEM), and a nonwoven graphite fabric (NWGF) anode. An additional carbon brush (CB) anode was placed adjacent to the tubular MEA. The MFC operated under semi-batch conditions with POME replacement every 7 days. Results showed superior performance of the AEM, with the highest power density (Pmax) observed in POME-treated MFCs. Current and power density increased with CB addition; the best chemical oxygen demand (COD) removal efficiency reached 73 %, decreasing from 1249 to 332 mg/L with three CBs. The Pmax was 0.18 W/m-2(-|-) with 1000 mg/L COD and three CBs, dropping to 0.0031 W/m-2(-|-) without CB and at 410 mg/L COD. Anode resistance, calculated using organic matter supplementation, COD, and anode surface area, decreased with increased COD or surface area, improving electricity production. AEM and CB compatibility synergistically enhanced MFC performance, offering potential for POME wastewater treatment and energy recovery.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Óleo de Palmeira , Óleos de Plantas , Fontes de Energia Bioelétrica/microbiologia , Óleo de Palmeira/química , Óleos de Plantas/metabolismo , Óleos de Plantas/química , Análise da Demanda Biológica de Oxigênio , Águas Residuárias/química , Resíduos Industriais , Eliminação de Resíduos Líquidos/métodos
10.
Environ Sci Pollut Res Int ; 31(11): 16629-16641, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38321283

RESUMO

In response to the escalating global issue of microbial contamination, this study introduces a breakthrough photocatalyst: bismuth ferrite-activated carbon (BFO-AC) for visible light-driven disinfection, specifically targeting the Gram-positive bacterium Staphylococcus aureus (S. aureus). Employing an ultrasonication method, we synthesized various BFO-AC ratios and subjected them to comprehensive characterization. Remarkably, the bismuth ferrite-activated carbon 1:1.5 ratio (BA 1:1.5) nanocomposite exhibited the narrowest band gap of 1.86 eV. Notably, BA (1:1.5) demonstrated an exceptional BET surface area of 862.99 m2/g, a remarkable improvement compared to pristine BFO with only 27.61 m2/g. Further investigation through FE-SEM unveiled the presence of BFO nanoparticles on the activated carbon surface. Crucially, the photocatalytic efficacy of BA (1:1.5) towards S. aureus reached its zenith, achieving complete inactivation in just 60 min. TEM analysis revealed severe damage and rupture of bacterial cells, affirming the potent disinfection capabilities of BA (1:1.5). This exceptional disinfection efficiency underscores the promising potential of BA (1:1.5) for the treatment of contaminated water sources. Importantly, our results underscore the enhanced photocatalytic performance with an increased content of activated carbon, suggesting a promising avenue for more effective microorganism inactivation.


Assuntos
Compostos Férricos , Nanocompostos , Staphylococcus aureus , Bismuto/farmacologia , Carvão Vegetal/farmacologia , Descontaminação , Luz , Catálise
11.
Membranes (Basel) ; 13(7)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37505045

RESUMO

Fruit juice is an essential food product that has received significant acceptance among consumers. Harmonized concentration, preservation of nutritional constituents, and heat-responsive sensorial of fruit juices are demanding topics in food processing. Membrane separation is a promising technology to concentrate juice at minimal pressure and temperatures with excellent potential application in food industries from an economical, stable, and standard operation view. Microfiltration (MF) and ultrafiltration (UF) have also interested fruit industries owing to the increasing demand for reduced pressure-driven membranes. UF and MF membranes are widely applied in concentrating, clarifying, and purifying various edible products. However, the rising challenge in membrane technology is the fouling propensity which undermines the membrane's performance and lifespan. This review succinctly provides a clear and innovative view of the various controlling factors that could undermine the membrane performance during fruit juice clarification and concentration regarding its selectivity and permeance. In this article, various strategies for mitigating fouling anomalies during fruit juice processing using membranes, along with research opportunities, have been discussed. This concise review is anticipated to inspire a new research platform for developing an integrated approach for the next-generation membrane processes for efficient fruit juice clarification.

12.
RSC Adv ; 13(13): 8985-8995, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36936853

RESUMO

River water has become contaminated with numerous hazardous compounds due to the rapid rise in population and industry expansion. Due to unchecked population growth and the improper disposal of electroplating industrial waste, issues with river water filtration and the elimination of chromium contamination have developed. Various technologies have been developed to overcome these problems. One of the technologies that have been proposed until now is membrane technology. On the other hand, the waste from plastic bottles, which grows yearly and now weighs 381.73 million tons, can create thin films or layers. Therefore, there is a lot of potential in employing plastic bottle trash as a low-cost, sustainable, and eco-friendly membrane material. In this study, the immersion-precipitation phase inversion method was used in the membrane preparation process from plastic bottle waste by modifying fillers (zeolite-NaY) and additives (LiCl and PEG-400) to improve membrane performance. The effect of filler and additive modification on the fabricated membrane was studied for its performance in water purification and chromium ion contaminant removal. The results demonstrated that the modified LiCl membrane performed optimally for water purification and the removal of chromium ions, along with a reduction in turbidity to 1.42 NTU (from 400 NTU) and a 54.75% removal of chromium.

13.
Membranes (Basel) ; 13(8)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37623788

RESUMO

Nanofibrous membranes for membrane distillation (MD) have demonstrated promising results in treating various water and wastewater streams. Significant progress has been made in recent decades because of the development of sophisticated membrane materials, such as superhydrophobic, omniphobic and Janus membranes. However, fouling and wetting remain crucial issues for long-term operation. This mini-review summarizes ideas as well as their limitations in understanding the fouling in membrane distillation, comprising organic, inorganic and biofouling. This review also provides progress in developing antifouling nanofibrous membranes for membrane distillation and ongoing modifications on nanofiber membranes for improved membrane distillation performance. Lastly, challenges and future ways to develop antifouling nanofiber membranes for MD application have been systematically elaborated. The present mini-review will interest scientists and engineers searching for the progress in MD development and its solutions to the MD fouling issues.

14.
Membranes (Basel) ; 13(5)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37233536

RESUMO

The occurrence of heavy metal ions in water is intractable, and it has currently become a serious environmental issue to deal with. The effects of calcining magnesium oxide at 650 °C and the impacts on the adsorption of pentavalent arsenic from water are reported in this paper. The pore nature of a material has a direct impact on its ability to function as an adsorbent for its respective pollutant. Calcining magnesium oxide is not only beneficial in enhancing its purity but has also been proven to increase the pore size distribution. Magnesium oxide, as an exceptionally important inorganic material, has been widely studied in view of its unique surface properties, but the correlation between its surface structure and physicochemical performance is still scarce. In this paper, magnesium oxide nanoparticles calcined at 650 °C are assessed to remove the negatively charged arsenate ions from an aqueous solution. The increased pore size distribution was able to give an experimental maximum adsorption capacity of 115.27 mg/g with an adsorbent dosage of 0.5 g/L. Non-linear kinetics and isotherm models were studied to identify the adsorption process of ions onto the calcined nanoparticles. From the adsorption kinetics study, the non-linear pseudo-first order showed an effective adsorption mechanism, and the most suitable adsorption isotherm was the non-linear Freundlich isotherm. The resulting R2 values of other kinetic models, namely Webber-Morris and Elovich, were still below those of the non-linear pseudo-first-order model. The regeneration of magnesium oxide in the adsorption of negatively charged ions was determined by making comparisons between fresh and recycled adsorbent that has been treated with a 1 M NaOH solution.

15.
Membranes (Basel) ; 13(3)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36984640

RESUMO

The hydrophobicity of metal-organic frameworks (MOFs) is critical in enhancing the separation process in membrane distillation. Herein, a new superhydrophobic University of Oslo 66 (UiO-66) MOFs was successfully constructed on the top of alumina hollow fibre (AHF) membrane for desalination purposes. The fabrication methodology of the membrane involved in situ growth of pure crystalline UiO-66 on top of AHF and post-synthetic modification by fluorosilane grafting. The resultant membrane was characterised to study the physicochemical properties of the pristine and modified membrane. A superhydrophobic UiO-66 with a contact angle of 163.6° and high liquid entry pressure was obtained by introducing a highly branched fluorocarbon chain while maintaining its crystallinity. As a result, the modified membrane achieved 14.95 L/m2∙h water flux and 99.9% NaCl rejection with low energy consumption in the direct contact membrane distillation process. Furthermore, the high surface energy contributed by UiO-66 is maximised to produce the maximum number of accessible sites for the grafting process. The synergistic effect of surface hydrophobicity and porous UiO-66 membrane in trapping water vapour shows great potential for desalination application.

16.
Nanomaterials (Basel) ; 13(6)2023 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-36985917

RESUMO

Polymeric membranes offer straightforward modification methods that make industry scaling affordable and easy; however, these materials are hydrophobic, prone to fouling, and vulnerable to extreme operating conditions. Various attempts were made in this study to fix the challenges in using polymeric membranes and create mixed-matrix membrane (MMMs) with improved properties and hydrophilicity by adding titanium dioxide (TiO2) and pore-forming agents to hydrophobic polyvinylidene fluoride (PVDF). The PVDF mixed-matrix ultrafiltration membranes in this study were made using the non-solvent phase inversion approach which is a simple and effective method for increasing the hydrophilic nature of membranes. Polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) as pore-forming chemicals were created. Pure water flux, BSA flux, and BSA rejection were calculated to evaluate the mixed-matrix membrane's efficiency. Bovine serum albumin (BSA) solution was employed in this study to examine the protein rejection ability. Increases in hydrophilicity, viscosity, and flux in pure water and BSA solution were achieved using PVP and PEG additives. The PVDF membrane's hydrophilicity was raised with the addition of TiO2, showing an increased contact angle to 71°. The results show that the PVDF-PVP-TiO2 membrane achieved its optimum water flux of 97 L/(m2h) while the PVDF-PEG-TiO2 membrane rejected BSA at a rate greater than 97%. The findings demonstrate that use of a support or additive improved filtration performance compared to a pristine polymeric membrane by increasing its hydrophilicity.

17.
Environ Sci Pollut Res Int ; 30(1): 259-273, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35902521

RESUMO

Various treatments of choice are available to overcome contamination of bisphenol A (BPA) in the environment including membrane technologies; however, the treatment still releases contaminants that threaten the human being. Therefore, the present study is conducted to investigate the degradation of BPA by recently developed visible-light-driven photocatalytic nitrogen-doping titanium dioxide (N-doped TiO2) dual-layer hollow fibre (DLHF) membrane and its efficiency in reducing the level of BPA in contaminated water. Fabricated with suitable polymer/photocatalyst (15/7.5 wt.%) via co-extrusion spinning method, the DLHF was characterized morphologically, evaluated for BPA degradation by using submerged photocatalytic membrane reactor under visible light irradiations followed by the investigation of intermediates formed. BPA exposure effects were accessed by immunohistochemistry staining of gastrointestinal sample obtained from animal model. BPA has been successfully degraded up to 72.5% with 2 intermediate products, B1 and B2, being identified followed by total degradation of BPA. BPA exposure leads to the high-intensity IHC staining of Claudin family which indicated the disruption of small intestinal barrier (SIB) integrity. Low IHC staining intensity of Claudin family in treated BPA group demonstrated that reducing the level of BPA by N-doped TiO2 DLHF is capable of protecting the important component of SIB. Altogether, the fabricated photocatalytic DLHF membrane is expected to have an outstanding potential in removing BPA and its health effect for household water treatment to fulfil the public focus on the safety of their household water and their need to consume clean water.


Assuntos
Luz , Titânio , Animais , Humanos , Catálise , Titânio/química , Trato Gastrointestinal
18.
RSC Adv ; 13(12): 7789-7797, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36909764

RESUMO

Industrial growth can have a good impact on a country's economic growth, but it can also cause environmental problems, including water pollution. About 80% of industrial wastewater is discharged into the environment without treatment, of which 17-20% is dominated by dyes, such as methylene blue (MB) and methyl orange (MO) from the textile industry. Only about 5% of a textile dye is used in the dyeing process and the rest is discarded. This problem, of course, requires special handling considering the harmful effects to health. On the other hand, the abundance of plastic waste is increasing by 14% or 85 000 tons per year. This problem must be solved due to its film-forming properties. High-density polyethylene (HDPE) is one type of plastic used as a membrane material. Therefore, in this study, HDPE plastic waste was utilized as a membrane for dye removal. In this study, HDPE plastic waste was fabricated via a thermal-induced phase-separation method using mineral oil as a solvent at various concentrations of 8%, 10%, 13%, and 15% (w/w). All the membranes were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and contact angle measurements. The results showed that the HDPE membrane at a concentration of 15% displayed the best performance compared to the others in terms of MB rejection. The negative charge (-36.9) of the HDPE membrane was more effective for cationic dye removal compared to the anionic dye. The flux and rejection of HDPE 15% for 100 ppm MB and MO removal were 2.71 and 4.93 L m-2 h-1, and 99.72% and 89.8%, respectively. The pure water flux of the membrane was 15.01 L m-2 h-1 and the tensile strength was 0.3435 MPa.

19.
Membranes (Basel) ; 13(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36837673

RESUMO

Lead (Pb) exposure can be harmful to public health, especially through drinking water. One of the promising treatment methods for lead contaminated water is the adsorption-filtration method. To ensure the cost-effectiveness of the process, naturally derived adsorbent shall be utilised. In this study, hydroxyapatite particles, Ca10(PO4)6(OH)2 (HAP) derived from waste cockle shell, were incorporated into the outer layer of polysulfone/HAP (PSf/HAP) dual-layer hollow fibre (DLHF) membrane to enhance the removal of lead from the water source due to its hydrophilic nature and excellent adsorption capacity. The PSf/HAP DLHF membranes at different HAP loadings in the outer layer (0, 10, 20, 30 and 40 wt%) were fabricated via the co-extrusion phase inversion technique. The performance of the DLHF membranes was evaluated in terms of pure water flux, permeability and adsorption capacity towards lead. The results indicated that the HAP was successfully incorporated into the outer layer of the membrane, as visibly confirmed by microscopic analysis. The trend was towards an increase in pure water flux, permeability and lead adsorption capacity as the HAP loading increased to the optimum loading of 30 wt%. The optimized DLHF membrane displayed a reduced water contact angle by 95%, indicating its improved surface hydrophilicity, which positively affects the pure water flux and permeability of the membrane. Furthermore, the DLHF membrane possessed the highest lead adsorption capacity, 141.2 mg/g. The development of a hybrid inorganic-organic DLHF membrane via the incorporation of the naturally derived HAP in the outer layer is a cost-effective approach to treat lead contaminated water.

20.
RSC Adv ; 12(23): 14411-14421, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35702242

RESUMO

Nanocellulose (NC) composite membranes containing novel ternary materials including NC, imidazole (Im), and mesoporous phosphotungstic acid (m-PTA) were successfully fabricated by a phase inversion method. The single-particle size of NC was 88.79 nm with a spherical form. A m-PTA filler with a mesopore size of 4.89 nm was also successfully synthesized by a self-assembly method. Moreover, the fabricated membrane NC/Im/m-PTA-5 exhibited the best performances towards its proton conductivity and methanol permeability at 31.88 mS cm-1 and 1.74 × 10-6 cm2 s-1, respectively. The membrane selectivity was 1.83 × 104 S cm-3.

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