Ultrafiltration Membrane Technology Research Articles

Structurally stable copolymer ultrafiltration membranes prepared via vinyl chloride suspension copolymerization and tannic acid in-situ modification integration

Polyvinyl chloride ultrafiltration membranes, widely used in various industries, are hindered by their high susceptibility to contamination. To address this concern, researchers have investigated diverse modification methods, encompassing surface modification and physical blending. Although surface modification provides stability, but it is intricate, expensive, and may result in pore clogging. Physical blending is a simpler approach but lacks durability and stability. Tannic acid (TA), a natural compound, has attracted attention for its potential in membrane modification due to its diverse benefits. However, the existing methods, such as TA-metal networks, encounter challenges of weakened stability and reduced permeability of membrane. To solve these issues, this research presents a novel approach that integrates suspension copolymerization, polyaddition, and a sol–gel process to fabricate structurally stable copolymer ultrafiltration membranes. Active sites for sol–gel reactions were embedded into the copolymer through copolymerization. Subsequently, TA was added to the copolymer casting solution, and isocyanate propyltriethoxysilane was decorated onto TA through a polyaddition reaction. Following this, a non-solvent induced phase separation method was used for membrane fabrication. During the formation of the membrane, a sol–gel reaction occurred between the copolymer and the modified TA, ensuring both stable chemical cross-linking. The membrane demonstrates excellent permeability, fouling resistance, and long-term operational stability. This innovative approach not only addresses compatibility and leakage issues associated with traditional methods but also ensures the stable integration of hydrophilic functional monomers within the copolymer matrix. The proposed method holds promise for advancing applications of ultrafiltration membrane technology in various complex environments.

Pengolahan Limbah Cair Industri Tahu Menggunakan Teknologi Ultrafiltrasi Dengan Sistem Monitoring Berbasis Internet of Things

Waste from the tofu industry is a byproduct of the tofu production process that can have negative environmental impacts if not managed properly. CV. Dapur Tahu still discharges liquid waste directly into the river, posing a potential threat of river water pollution. Although a new reservoir and waste disposal channel are under construction, there is currently no effective waste treatment facility in place. To address this issue, a tofu wastewater treatment facility utilizing filtration technology is proposed due to its simplicity of operation, durability, and high efficiency in removing organic contaminants. The technology comprises a multi-stage filtration process involving sand filters (pumice, zeolite, and activated charcoal) combined with ultrafiltration membrane technology, complemented by a monitoring system consisting of TDS, pH, and temperature sensors. The multi-stage filtration process is capable of reducing TDS levels to 160 ppm, resulting in visibly clearer wastewater compared to the initial turbid white condition. The installation of IoT-based monitoring devices in the wastewater treatment process significantly aids in real-time water quality monitoring, accessible via mobile phone screens.

Membrane fouling and control in algae-rich water treatment

Microfiltration and ultrafiltration membrane technology has now become one of the important methods for algae-rich water treatment due to its better solid-liquid separation effect and microbial retention capacity, while the existence of membrane fouling has been restricting the full-scale promotion and application of low-pressure membrane technology. The main foulants causing membrane fouling in algal-rich water include algal cells, algal debris and algal organic matter AOM (EOM and IOM). In this paper, the mechanism of membrane fouling caused by algal foulants in MF/UF for high algal water treatment is analysed in terms of both individual and composite fouling. Both individual and composite effects of algal foulants can lead to severe membrane fouling, in which algal cells and algal debris mainly dominate the accumulation of filter cake, while AOM mainly leads to membrane pore blockage membrane fouling is exacerbated by compounding effects, with severe reversible and irreversible fouling caused by filter cake formation and membrane pore shrinkage. This paper also discusses several common membrane fouling control methods, including pretreatment (oxidation, coagulation, combined oxidation-coagulation and adsorption) and membrane modification, and it is found that these several membrane fouling control methods can achieve good results.

Preparation and Characterization of Polyethersulfone/Activated Carbon Composite Membranes for Water Filtration.

Ultrafiltration membrane technology holds promise for wastewater treatment, but its widespread application is hindered by fouling and flux reduction issues. One effective strategy for enhancing ultrafiltration membranes involves incorporating activated carbon powder. In this study, composite polyethersulfone (PES) ultrafiltration membranes were fabricated to include activated carbon powder concentrations between 0 and 1.5 wt.%, with carbon size fixed at 200 mesh. The ultrafiltration membranes were evaluated in terms of membrane morphology, hydrophilicity, pure water flux, equilibrium water content, porosity, average pore size, protein separation, and E-coli bacteria removal. It was found that the addition of activated carbon to PES membranes resulted in improvements in some key properties. By incorporating activated carbon powder, the hydrophilicity of PES membranes was enhanced, lowering the contact angle from 60° to 47.3° for composite membranes (1.0 wt.% of activated carbon) compared to the pristine PES membrane. Water flux tests showed that the 1.0 wt.% composite membrane yielded the highest flux, with an improvement of nearly double the initial value at 2 bar, without compromising bovine serum albumin rejection or bacterial removal capabilities. This study also found that the inclusion of activated carbon had a minor impact on the membrane's porosity and equilibrium water content. Overall, these insights will be beneficial in determining the optimal concentration of activated carbon powder for PES ultrafiltration membranes.

Ceramic membrane with double catalytic layer for efficient peroxymonosulfate activation and dissolved organic matter (DOM) membrane fouling control

Membrane fouling and low removal of dissolved organic matter (DOM) are the main obstacles for the wide application of ultrafiltration membrane technology in water treatment. Herein, we reported the preparation and application of a novel ceramic membrane, which embedded the cobalt oxide in the membrane support layer, and simultaneously loaded the CoAl composite bimetallic oxide on membrane surface layer. The double catalytic layer membrane (CoAl@AM-Co) enabled more efficient DOM removal and membrane fouling mitigation via in situ peroxymonosulfate (PMS) activation during filtration of actual raw water. Compared to the ceramic membrane with only single catalytic layer, the CoAl@AM-Co/PMS system could achieve much higher normalized membrane flux (0.79 vs. 0.63 and 0.49) and TOC removal (87.47 % vs. 58.35 % and 47.16 %); meanwhile, the molecular weight of DOM in the permeate water would also be significantly decreased. The FT-ICR MS results indicated that the total amount of DOM molecules of the permeate was reduced; the DOM with high H/Cwa and low O/Cwa value could be more easily removed, accompanied with the production of DOM with higher oxidation and unsaturation degree. Singlet oxygen and surface-bound radicals were proved to play a critical role in mitigating the membrane fouling by DOM. The design of ceramic membrane equipped with double catalytic layer and its application in advanced water purification were systematically elucidated for the first time in this work, which provided a new pathway for efficient treatment of surface water containing DOM.

Recent developments in ultrafiltration membrane technology for the removal of potentially toxic elements, and enhanced antifouling performance: A review

The presence of high concentrations of heavy metals (potentially toxic elements) in water bodies generates serious environmental issues and health problems that led to a dramatic increase in wastewater treatment costs. Therefore, it is imperative to develop low-cost and efficient technologies for removing these contaminants from wastewater. Membrane processes are advanced techniques for water treatment and ultrafiltration membrane (UF) has some advantages over other membranes as it requires low pressure to perform However, the UF membrane separates contaminants mainly by size exclusion mechanism, resulting in poor decontamination performance for potentially toxic elements and high susceptibility to membrane fouling. The performance of the UF membrane is often affected by organic and biofouling. Hence, researchers are still looking forward to developing new types of UF membranes that will make them more effective for potentially toxic elements removal and overcome the obstacle of fouling. This review aims to provide an overview of the application of UF membranes in potentially toxic element removal through bibliometric analysis and literature review. The incorporation of various organic, inorganic, carbon-based, and composite-based nano-materials into polymers such as zeolites, metal–organic frameworks (MOFs), and graphene oxide (GO) gave encouraging results for the removal of potentially toxic elements from water. Moreover, this review discusses the mechanisms of fouling in UF membranes and how different techniques can be used to control it. In the end, all the materials are evaluated and compared based on their efficiency, toxicity, simplicity in preparation, popularity, and cost efficiency to provide an overall critical view of the work done in this area. Also, the major challenges and limitations of the use of UF membranes are provided which will help to set the direction of future research.

Preparation of a CAB-GO/PES Mixed Matrix Ultrafiltration Membrane and Its Antifouling Performance.

Serious membrane fouling has limited the development of ultrafiltration membrane technology for water purification. Synthesis of an ultrafiltration membrane with prominent anti-fouling ability is of vital importance. In this study, CAB-GO composite nanosheets were prepared by grafting graphene oxide (GO) with a zwitterionic material cocamidopropyl betaine (CAB) with strong antifouling properties. Anti-fouling CAB-GO/PES mixed matrix ultrafiltration membrane (CGM) was prepared by the phase inversion method with polyethersulfone (PES). Due to its electrostatic interaction, the interlayer distance between CAB-GO nanosheets was increased, and the dispersibility of GO was improved to large extent, thereby effectively avoiding the phenomenon of GO agglomeration in organic solvents. Based on the improvement of the surface porosity and surface hydrophilicity of the CAB-GO/PES mixed matrix membrane, the pure water flux of CGM-1.0 can reach 461 L/(m2·h), which was 2.5 times higher than that of the original PES membrane, and the rejection rates toward BSA and HA were above 96%. Moreover, when the content of CAB-GO was 0.1 wt%, the prepared CAB-GO/PES membrane exhibited very high BSA (99.1%) and HA (98.1%) rejection during long-term operation, indicating excellent anti-fouling ability.

Preparation Process Optimization of Peptides from Agaricus blazei Murrill, and Comparison of Their Antioxidant and Immune-Enhancing Activities Separated by Ultrafiltration Membrane Technology.

Agaricus blazei murrill (ABM), a large fungus, is reported to have extensive biological activities but the antioxidant and immune-regulatory capacities have been less studied and the components responsible for the functions are unclear. This study prepared ABM peptides (ABMP) using ultrasound-assisted enzymatic extraction (UAEE) strategy and cascade ultrafiltration (UF) membrane technology. The UAEE extraction conditions were optimized using response surface methodology (RSM) with four factors and three levels to achieve the maximum ABMP yield (34.03%); the optimal conditions were an enzyme amount of 4%, ratio of ABM to water of 1:30, ultrasonic power of 360 W, and ultrasonic time of 30 min. Four ABMP fractions were obtained after UF with different pore size and their antioxidant and immune-regulatory abilities were evaluated and compared. The results showed that they could effectively scavenge DPPH, hydroxyl, and ABTS radicals, especially for ABMP-2; the scavenging rate of the above radicals were 79.31%, 63.60%, and 96.08%, respectively. In addition, four ABMP fractions also activated macrophage activity through strengthening phagocytosis and the production of NO, IL-6, IL-1β, and TNF-α in a dose-dependent manner. Notably, the ABMP-2 fraction with a MW of 3-5 kDa and peptide purity of 82.88% was found to have the best effect, showing the maximum phagocytosis (189.37%) as well as NO (7.98 μM), IL-6 (195.05 pg/mL), IL-1β (876.15 pg/mL), and TNF-α (1620 pg/mL) secretion at a treatment concentration of 150 μg/mL. The findings indicated that the ABMP, especially for the separate ABMP-2, could be used as dietary supplements and have the potential to be exploited as immune-enhancing agents.

Evaluation of an ultrafiltration membrane for the removal of fish viruses and bacteria in aquaculture water

Ultrafiltration (UF) membranes are used to successfully remove waterborne virus and bacteria from wastewater and drinking water. However, UF membrane application in aquaculture water treatment is limited. In this study we evaluate the performance of a capillary polyethersulfone UF membrane to remove two benchmark waterborne fish pathogens: i) the infectious pancreatic necrosis virus - IPNV, which is an unenveloped icosahedral virus, and ii) the bacterium Aeromonas salmonicida, which is a Gram-negative, facultative anaerobic bacilli. Moreover, the UF membrane bench-scale unit was tested at two temperatures according to salmonid aquaculture: low (4 - 7°C) and high (16 - 19°C). Sterilised natural seawater was spiked with laboratory cultured pathogens, the water was filtrated, and the membrane permeate collected. Both pathogen solution and permeate were evaluated using a cell culture method to estimate the colony-forming units (CFU/ml) for bacteria presence, a median tissue culture infectious dose (TCID50/ml) assay for virus presence, and real-time quantitative polymerase chain reaction (RT-qPCR) for both bacteria and virus presence. The membrane permeate was negative for both virus and bacteria for all analysis and for both low and high temperatures. The results from this bench-scale study are encouraging for the application of UF membrane technology in aquaculture water treatment to prevent virus and bacteria outbreaks. Further studies should validate this UF membrane technology results in commercial aquaculture conditions.

Industrial Pilot for Assessment of Polymeric and Ceramic Membrane Efficiency in Treatment of Liquid Digestate from Biogas Power Plant

Due to the depletion of available water resources and the consistently rising environmental pollution levels, the exploitation of the digestate generated as an unfavorable by-product of the industrial wastewater treatment plants, could not only offer a readily available source of recycled water, but also an efficient agricultural fertilizer. However, the first step for the utilization of the digestate is the removal of any potentially harmful contaminants, and ultrafiltration membranes can provide successful remediation routes in this direction. This work investigates the industrial pilot-scale purification and reusability of the liquid digestate derived from the anaerobic treatment of waste mixtures of high organic content, using ultrafiltration membrane technology. Two different types of ultrafiltration membranes, polymeric and ceramic, were evaluated regarding their efficiency and long-term performance, parameters that heavily affect the overall costs of the operational unit. Our results indicate that the ceramic membranes exhibited a superior performance compared to its polymeric analogues, such as a higher flux, as well as significantly increased lifetime, signifying promising cost-effective and long-term applicability on an industrial level. In addition, the analytical physicochemical characterization of the ultrafiltration reject indicated its high nutrient value, suggesting its highly promising exploitation as an added value fertilizer, further enhancing the sustainability of the proposed approach.

Briefly Talking about the Application of Ultrafiltration Membrane Technology in Water Treatment of Environmental Engineering

Briefly Talking about the Application of Ultrafiltration Membrane Technology in Water Treatment of Environmental Engineering

Analysis on Study on Application of Ultrafiltration Membrane Technology in Environmental Engineering Water Treatment

Analysis on Study on Application of Ultrafiltration Membrane Technology in Environmental Engineering Water Treatment

Application of ultrafiltration membrane technology in environmental engineering water treatment

Application of ultrafiltration membrane technology in environmental engineering water treatment

Ultrafiltration Membrane Technology for Oily Wastewater Treatment

Oil and gas sectors generate large amounts of oily wastewater, which is called produced water. In which, it contains high concentrations of hazardous organic and inorganic pollutants. This paper attempts to evaluate the performance and quality of using a polyethersulfone ultrafiltration membrane (UFM) to treat the produced water of Al-Ahdab oil field (Wassit, Iraq). 8 rectangular flat sheets of polyethersulfone ultrafiltration membrane were used. The area of each is 60 cm2 and pore size about 15 nm used in the experimental work. Prepared UFM is characterized by determining the surface morphology by scanning electron microscopy (SEM). The result showed that the UFM indicated high removal efficiency in all parameters and especially oil and grease and total suspended solid but in general it still less than the requirement of water reuse. The results showed that, a combination of a conventional treatment method and UFM technology have higher efficiency than using UFM only.

Ultrafiltration concentrated biogas slurry can reduce the organic pollution of groundwater in fertigation

Biogas slurry has the problems of having a low concentration, having a large production volume, and containing many small-molecule organic pollutants. During the fertigation process of biogas slurry, many small-molecule organic pollutants may pose potential pollution risks to groundwater. In this study, the ultrafiltration membrane technology was used to separate small-molecule organics in the biogas slurry to prepare ultrafiltration concentrated biogas slurry (UCBS). To research the impact of UCBS and raw biogas slurry (RBS) on the small-molecule organic pollution of groundwater, a laboratory soil column simulation leaching device was used to conduct leaching experiments with 4 types of UCBS and RBS in acric ferralsols and hydragric anthrosols for two quarters (8 fertilization periods). The results of the study show that both UCBS and RBS caused nitrate pollution to groundwater. UCBS has a lower risk of organic pollution to groundwater than RBS. Irrigating UCBS in hydragric anthrosols has a higher risk of organic pollution of groundwater than that in acric ferralsols. Analysis of the molecular weight distribution of dissolved organic matter (DOM) in the leaching solution showed that the organic pollutants were mainly small molecules <10 kDa. According to 3D excitation-emission matrix (3D-EEM) analysis, the main organic pollutants in the leaching solution were fulvic acid, microbial protein metabolites and humic acid organic compounds. The research results show that the pretreatment of biogas slurry by ultrafiltration can reduce the risk of small-molecule organic pollution of groundwater in land application, which can provide a new scientific basis to standardize biogas slurry land application technical guidelines and reduce groundwater pollution.

Study on Application of Ultrafiltration Membrane Technology in Environmental Engineering Water Treatment

Study on Application of Ultrafiltration Membrane Technology in Environmental Engineering Water Treatment

High performance ultrafiltration membrane by coupling magnetic migration and in-situ surface modification

Ultrafiltration (UF) membrane technology has drawn much attraction during the past decades to address the challenge of global clean water scarcity. Herein, we proposed a facile methodology to prepare a gradient polysulfone-based (PSf) UF membrane with effective antifouling properties via coupling magnetic field-assisted directional migration and in-situ hydrolysis of fluoro-agent during non-solvent induced phase separation (NIPS). The effect of GO-Fe3O4 gradient distribution and fluorosilane (FAS) in-situ surface modification on membrane morphology, hydrophilicity, porosity, water flux and antifouling properties have been investigated. Optical microscopy and SEM-EDX observations indicated that hydrophilic GO-Fe3O4 nanofiller could directionally migrate in casting solution and eventually result in gradient distribution in PSf matrix under the magnetic field. In addition, the surface enrichment of GO-Fe3O4 provided reaction sites to anchor low energy FAS via in-situ hydrolysis on the membrane surface and realized dual antifouling mechanism (fouling-resistance and fouling-release), which guaranteed UF membranes with excellent antifouling properties and remarkable long-term stability and reusability. Our study provided a new incentive to the development of high performance UF membranes by coupling magnetic migration and in-situ surface modification.

A novel strategy to alleviate ultrafiltration membrane fouling by rotating membrane module

Integrated ultrafiltration (UF) membrane technology has attracted extensive attention in drinking water treatment due to its excellent performance and small footprint. However, membrane modules normally are static in membrane tanks, which cause a gradual increase in the cake layer thickness over time, thus resulting in severe membrane fouling. To overcome this shortcoming, we report an effective strategy to regulate cake layer thickness by rotating the membrane module in the presence of flocs. The results showed that the cake layer thickness can be effectively reduced because of the floc looseness, resulting in the alleviation of membrane fouling. The higher the module rotation speed, the higher the flow velocity in the membrane tank and the larger the shearing force on the cake layer surface. As a result, the membrane fouling was considerably mitigated, and it was interesting that the pollutant removal efficiency was hardly influenced. With module rotation, we found that acid solutions displayed a better performance in removing pollutants (even low molecular weight pollutants) and alleviating membrane fouling compared to the alkaline conditions because of the smaller floc size, larger floc specific surface area, and higher floc positive charge. Additionally, an excellent UF membrane performance was also observed with the raw water taken from the South-North water in China. Collectively, this study demonstrated that floc-based cake layers can be effectively regulated with module rotation, which has a great potential in drinking water treatment application, particularly in small water plants.

High-performance chlorinated polyvinyl chloride ultrafiltration membranes prepared by compound additives regulated non-solvent induced phase separation

To enable wider deployment of ultrafiltration (UF) membrane technology, novel advanced membrane materials are still highly desired. Chlorinated polyvinyl chloride (CPVC) shares most of the outstanding features of polyvinyl chloride (PVC) and possesses improved thermal stability, indicating a promising material for UF membrane. To date, however, the separation performance of the current CPVC UF membranes is far below the requirements for application. In this study, propylene glycol and polyoxyethylene-20-sorbaitan monolaurate (Tween-20) were selected as compound additives to manipulate the structure and separation performance of CPVC membrane fabricated by the non-solvent induced phase separation process. The results demonstrated that the synergistic effect of compound additives led to instantaneous demixing to increase the ratio of polymer lean phase in the initial casting film, and the rapid precipitation fixed the phase separation structure immediately. Consequently, the prepared membranes possessed improved porosity and pore size uniformity. The obtained CPVC UF membranes exhibited a high pure water flux up to 955.2 L m-2 h-1·bar-1 with a BSA rejection above 95.0%, which is 11 times higher than CPVC membrane fabricated without additive and comparable to that of commercial UF membranes. In addition, thanks to the more uniform pore size distribution and smooth top surface, the obtained CPVC membranes also exhibited good antifouling performance. Moreover, the CPVC UF membrane showed good thermal stability and reuse performance, which would facilitate its post-functionalization and practical application.

Optimization of operating parameters for xylose reductase separation through ultrafiltration membrane using response surface methodology

The application of the xylose reductase (XR) enzyme in the development of biotechnology demands an efficient and large scale enzyme separation technique. The aim of this present work was to optimize xylose reductase (XR) purification process through ultrafiltration membrane (UF) technology using Central composite design (CCD) of response surface methods (RSM). The three effective parameters analyzed were filtration time (0–100), transmembrane pressure (TMP) (1–1.6 bar), cross flow velocity (CFV) (0.52–1.2 cm/s−1) and its combined effect to obtain high flux with less possibility of membrane fouling. Experimental studies revealed that the best range for optimization process for filtration time, operational transmembrane pressure and cross flow velocity was 30 min, 1.4 bars and 1.06 cm/s, respectively as these conditions yielded the highest membrane permeability (56.03 Lm-2h-1 bar−1) and xylitol content (15.49 g/l). According to the analysis of variance (ANOVA), the p-value (<0.0001) indicated the designed model was highly significant. The error percentage between the actual and predicted value for membrane permeability and xylitol amount (2.21 % and 4.85 % respectively), which both were found to be close to the predicted values. The verification experiments gave membrane actual permeability of 57.3 Lm-2h-1 bar−1 and 16.29 g/l of xylitol production, thus indicating that the successfully developed model to predict the response.