Membrane Filtration Research Articles

Separation of oil from rapeseed protein rich extracts by microfiltration using hydrophilic ceramic membranes

Rapeseed, containing up to 40 % protein along with a well-balanced profile of essential amino acids, stands out as a promising novel plant-based protein source. Yet, protein extraction faces challenges, due to adverse effects of oil extraction on protein properties and down-stream processing. In this work was explored the potential of using hydrophilic silicon carbide ceramic (SiC) membranes to separate oil from a protein rich extract and produce permeates rich in protein and retentates containing oleosomes. Various solvents including water, sodium chloride, alkaline (pH 8.5) and a complex alkaline salt solvent were used to obtain a variety of protein and oil extracts from the whole rapeseeds. The type of solvent significantly affected the composition and colloidal structure of the feed which has minor effect on the oil separation but significant effect on filtration performance and composition of the permeates and retentates obtained. The membrane filtration process achieved significant oil separation, with permeates exhibiting minimal oil content ranging from 0.1 to 1.3 % (w/w), for water and alkaline solvents respectively. Assessment of the filtration performance showed fluxes from 23 to 50 L·h−1·m−2 and final volume concentration ratios of 1.3, 1.4, 1.6 and 1.9 for salt, alkaline-salt, alkaline and water solvents. The retentate, composed of 11.8–19.8 % protein and 23.6–28.7 % w/w dry matter, is a relevant and innovative ingredient for plant food formulations. These findings show the potential of membrane filtration with SiC in enabling removal of oil and producing streams with potential for diverse applications in the food industry.

Fabrication and characterization of poly(methyl vinyl ether maleic anhydride) blended poly(lactic acid) ultrafiltration membrane with upgraded antifouling and separation performance

In this present study, a novel environment-friendly bio-polymeric hybrid ultrafiltration membrane was fabricated by incorporating poly(methyl vinyl ether maleic anhydride) (PMVEAMA) into the poly(lactic acid) (PLA) polymer matrix. The integration of PMVEAMA into PLA significantly altered the membrane's structural morphology, functional characteristics, and filtration performance. As a result, key functional parameters like membrane porosity and water content were increased, which exhibiting the improved hydrophilicity. Furthermore, the molecular weight cut-off of the PLA/PMVEAMA membrane reached up to a maximum of 66.5 KDa with an average pore size of 9.14 nm, subsequently improving the flux of the membrane up to 2.8 times than PLA membrane. The functional capacity of the synthesized membrane was further assessed by testing its ability to filter toxic chlorophenolic compounds. Rejection studies reveal that the PLA/PMVEAMA membrane achieved a rejection efficiency of 44.64 % pentachlorophenol (PCP) and 51.85 % 2,4-dichlorophenol (DCP). Moreover, fouling studies revealed enhanced PCP and DCP flux recovery ratios of 50.94 % and 51.40 %, respectively, with a significant reduction in the flux decline rate. Additionally, the synthesized PLA/PMVEAMA membranes improved stability and regenerative properties up to 12 filtration cycles and antifouling properties highlight its potential to filter chlorophenolic compounds from wastewater.

Optimization of iron flocculation for enrichment of CyHV-2 in aquaculture water

Cyprinid herpesvirus 2 (CyHV-2) is an important infectious virus endangering the farmed Carassius species industry. The enrichment and identification of CyHV-2 in the water is a vital means of early warning diagnostics, which is helpful to aquatic diseases prevention and control. In this study, we employed and optimized iron flocculation to enrich the concentrations of CyHV-2 in aquaculture water. Different Fe3+ concentrations (0.5, 1.0, and 10.0 mg/L), various membrane filters (mixed cellulose ester, glass fiber, nylon microporous filter membrane), different elution buffers containing reductants (ascorbate, citrate, DL-malate, and their combinations with EDTA or TE buffer) were compared to check the recovery yield of CyHV-2. Viral genome quantitation was determined using quantitative real-time PCR. The results showed that Fe3+ concentration of 1.0 mg/L, the glass fiber and citrate-TE were determined to have high efficiency and stable recovery yield. To evaluate infectious CyHV-2 viral titres, crucian carps (Carassius auratus) were intraperitoneally injected with CyHV-2. The mortality rate was 100 % at 9 days postinoculation (dpi) with the 96.7 % detection of CyHV-2 in the pooled tissues. The histopathological phenotype showed necrotic cell death in the liver, spleen and kidney. The CyHV-2 genome was ranging from 101.1 to 107.5 copies/μl in the deceased fish, and 101.4 to 103.0 copies/μl in the feeding water at various stages from latent infection to onset of disease. The field samples from Huzhou, Zhejiang Province on June 4th and 7th had higher detection rates, 87.5 % and 100 % respectively, corresponding to higher CyHV-2 detected in the aquaculture water. CyHV-2 viral load in cultured waters tends to increase prior to fish death, which provides a new indicator for the prediction of fish diseases. In summary, we have established a unified operational standard for enrichment of CyHV-2 in the aqueous environment by iron flocculation.

Fabrication and evaluation of PVDF membranes modified with cellulose and cellulose esters from peanut (Arachis hypogea L.) shell for application in methylene blue filtration

Polyvinylidene fluoride (PVDF) membrane is frequently employed for filtration due to its excellent properties. The hydrophobicity of PVDF membrane causes easy fouling; therefore, hydrophilic polymer materials are required to increase hydrophilicity. This study applies cellulose and cellulose esters as fillers for PVDF membranes to solve the fouling problem. Cellulose esters, such as cellulose acetate (PSCA), cellulose benzoate (PSCB), and cellulose citrate (PSCC), were successfully synthesized from peanut shell cellulose (PSC) using Fischer and non-Fischer reactions. The phase inversion method was successfully used to fabricate PVDF membranes with cellulose or cellulose esters as fillers. The fabricated membranes have been applied for methylene blue (MB) filtration. Adding PSC fillers improved the hydrophilicity and performance of the PVDF membranes up to 23.49 ± 2.40 L m−2 h−1 for water flux and 95.75 ± 0.78 % for rejection of MB. Regarding cellulose esters, cellulose acetate gave the highest value of 77.63 L m−2 h−1 for water flux, and cellulose citrate gave the highest value of 86.88 ± 3.54 % for MB rejection. Hence, cellulose or cellulose esters from peanut shells are suitable fillers for MB filtration in PVDF membranes.

Emergence of microplastics in African environmental drinking water sources: A review on sources, analysis and treatment strategies

The emergence of microplastics (MPs) as microcontaminants in environmental drinking water sources is a problem in Africa that requires immediate action. Therefore, this review focused on understanding the sources of MPs in African water systems, treatment strategies, analytical methods for identification and quantification, and Africa's pollution index. From the findings, the source of MPs in African water systems was attributed to unregulated importation of plastic products, poor waste management, lack of awareness, poor environmental value system and the inability of local polymer industries to adjust to new policies on plastic management. Most studies identified microfibers and microbeads to be the primary sources of plastics that break down to MPs in African drinking water sources, with polystyrene (PS), polypropylene (PP), and polyethylene (PE) being frequently detected. Current methods for identification, and quantification of MPs in most studies conducted in Africa were not developed in Africa but was adopted from developed countries and, in some cases, modified to meet specific analytical requirements. More studies are necessary for in-depth understanding of the fate and pollution index of MP in African environmental water systems. Furthermore, the interaction between MP and other pollutants in the water system still needs to be better understood. This review suggests membrane and rapid sand filtration methods as promising methods that may be considered for removing MPs from water systems in Africa.

A novel electrochemical membrane filtration system operated with periodical polarity reversal for efficient resource recovery from nickel nitrate laden industrial wastewater

The economical and efficient removal of nickel nitrate from industrial wastewater remains a challenge. Herein, we developed an innovative electrochemical membrane filtration system that used a periodic polarity reversal process to adjust the acid-base environment near membrane interface for the recovery of nickel (II) and ammonia. The Ru based electrocatalytic layer could boost the selective reduction of nitrate to ammonia by generating atomic hydrogen, resulting in the precipitation of Ni2+ by the increasing pH at the membrane interface. Then, the precipitation of Ni(OH)2 could be effectively stripped and collected under the periodic polarity reversal process. In-situ interfacial measurements demonstrated that the polarity reversal process enabled a reversible transformation between strongly acidic (pH < 2) and alkaline (pH > 13) environments within a 200 µm range at the membrane interface. In continuous flow operation treating real industrial wastewater containing 96.7 mg-N L−1 nitrate and 135.0 mg L−1 Ni2+, the system demonstrated the capability to achieve 92.5 ± 2.6 % nitrate removal (with a recovery efficiency of 15.1 ± 1.9 g-NH3 kWh−1) and 99.7 ± 0.1 % Ni²⁺ removal (with a recovery efficiency of 24.9 ± 2.4 g-Ni kWh−1). Additionally, the specific treatment cost was approximately $0.17 m−3, attributed to the recovery of Ni(OH)₂ and ammonia. Furthermore, this system could deliver a significant economic benefit ($1.64 per m3) for treating a high concentration real wastewater (331.5 mg-N L−1 nitrate and 1496.3 mg L−1 Ni2+), outperforming traditional alkali precipitation and biological nitrification/denitrification processes. Overall, our study presents an economical and sustainable method for recovering valuable chemicals from wastewater containing heavy metals and inorganic nitrogen, potentially advancing cost-effective water treatment technologies.

Causes of negatively charged meso-colloids formed in the coagulation process: Implication of the origin of foulants in the coagulation–membrane filtration process

Tiny colloids with a size similar to that of membrane pores are responsible for irreversible fouling in the pre-coagulation microfiltration membrane filtration process for drinking water treatment. Such colloidal particles are defined here as meso‑colloids, and the charge neutralization of meso‑colloids is demonstrated to be a key to controlling irreversible fouling. However, meso‑colloids remain negatively charged at neutral pH, the reason for which is still unclear. To increase the efficiency of membrane operation, additional knowledge about the causes and behaviors of meso‑colloids during pre-coagulation is indispensable. Therefore, in this study, meso‑colloids are fractionated after a series of jar tests, and their exact composition and charge properties are characterized. Two natural water samples, the adjusted water consisting of meso‑colloid fraction separated from one of the natural water samples and additional inorganic chemicals, and the adjusted water by the addition of appropriate inorganic chemicals into pure water are used for jar tests, which are conducted with and without the addition of the coagulant polyaluminum chloride (PACl). After the jar tests using two natural water samples, all of the meso‑colloids exhibit a negative charge under the conditions applied for the jar tests, indicating that charge neutralization is difficult. The composition of the meso‑colloids is found to be completely different depending on the water source used. Organic-rich water tends to generate meso‑colloids with a low Al/C (mass ratio of aluminum and organic carbon) ratio. In contrast, organic-poor water tends to produce meso‑colloids with a high Al/C ratio. From the results of the jar tests using two kinds of adjusted water samples, it is found challenging to neutralize meso‑colloids by PACl at neutral pH, because the overdose and underdose of PACl result in negatively charged biopolymer or negatively charged aluminum species. Therefore, the development of a new coagulant for specific use in the coagulation membrane filtration process is proposed, which can minimize the formation of negatively charged species even at neutral pH.

Establishment of efficient system for bagasse bargaining: Combining fractionation of saccharides, recycling of high-viscosity solvent and dismantling

Sugarcane bagasse (SCB) has a recalcitrant structure, which hinders its component dismantling and subsequent high value utilization. Some organic solvents are favorable to dismantle lignocellulose, but their high viscosity prevents separation of components and reuse of solvents. Herein, ethylene glycol phenyl ether (EGPE)-acid system is used as an example to develop green and efficient methods to dismantle SCB, purify polysaccharides and lignin, and reuse solvents. Results show that dismantling SCB at 130 °C, 0.5 % H2SO4, and 100 min can obtain 85.5 % cellulose recovery, 94.1 % hemicellulose removal and 83.7 % lignin removal. Different molecular weight saccharides are separated by membranes filtration and centrifugation, and lignin recovered by antisolvent precipitation. The solvent recovered by distillation, achieving high dismantling efficiency of 89.2 % cellulose recovery, 94.1 % hemicellulose removal and 94.4 % lignin removal after four recycles. Results show a promising approach for the closed-loop process of dismantling lignocellulose, fractionating saccharides, and reusing solvents in high-viscosity systems.

Modified PVDF/PMMA/SiO2 composite nanofibrous membrane in airborne filtration: Transparency, mechanical properties and filtration performance

A comprehensive study on four modified Polyvinylidene Fluoride (PVDF) nanofibrous membrane was conducted to fabricate transparent air filters for the first time when adding Polymethyl methacrylate (PMMA) and SiO2. The modified PVDF nanofibrous membrane properties were extensively characterized using scanning electron microscopy, infrared analysis, crystallinity, and investigated the optical transparency, mechanical properties, and filtration performance. The enhancement of PMMA is greater than the weaken of SiO2 with the PVDF/PMMA/SiO2 membrane average transparency of 70.48 %. The PVDF membrane mechanical strength enhanced by SiO2 and weakened by PMMA is visualized by a Weibull two-parameter distribution model. The PVDF/PMMA/SiO2 membrane filtration efficiency is 94.12–96.39 %, and the impressive quality factor (Qf) of 0.074 Pa⁻1 is superior to other three modified membranes in filtration performance while maintaining the sufficient ultimate tensile strength (UTS) of 20.41±0.28 MPa.

A Mini Review on the Opportunities for Membrane Pervaporation Technology for Energy-efficient Removal of Dispersed Oil and Dissolved Hydrocarbons from Produced Water

Produced water is reported to have the largest volume of waste stream associated with hydrocarbon recovery. It was estimated to increase from 250 million B/D in 2007 to more than 300 million B/D between 2010 and 2012. Market research conducted by Adroit put the globally produced water treatment market at a value of USD 5.10 billion in 2022. This value is anticipated to be USD 9.80 billion in 2032 at a compound annual growth rate (CAGR) of 5.80% over the prediction period. Oil and gas companies have been mandated to comply with the newly enacted environmental regulations that require extensive treatment of this water before discharge or reuse. The limited quantity of freshwater resources coupled with the increasing oil and gas production activities has made it necessary for all stakeholders to look for sustainable management of this water. Presently, a certain percentage of produced water is reused while the rest is discharged into the ocean. In both cases, the water needs to be thoroughly treated. The choice of technologies for produced water treatment depends on numerous factors, such as the chemical composition of the water and the level of purity that must be attained before disposal, recycling, or re-use. Some of the technologies used for produced water treatment include physical separation methods such as gravity, adsorption, filtration, coalescence, cyclones, flotation, centrifuges, membranes, and oxidation. There are also chemical and biological separation methods. Contaminants such as small droplets of dispersed oil and dissolved hydrocarbons (DODHs) are very challenging to remove using the above-listed water treatment technologies. Moreover, the use of membrane technology has been limited only to the use of reverse osmosis and membrane filtration for removing salinity, metals, and other inorganics. This article highlights the opportunities for the use of membrane vapor permeation and pervaporation for the removal of the small droplets of DODHs, which have been reported to be very challenging contaminants to remove. The use of 3D printing technology for the fabrication of membrane materials was reviewed. The 3D membrane development method can be used to fabricate almost any shape of the material in a highly customized manner using computer-aided design. The information presented in this article will serve as a useful reference for the technologies used for a sustainable water treatment strategy in the oil and gas industry.

Advancements in Inorganic Membrane Filtration Coupled with Advanced Oxidation Processes for Wastewater Treatment.

Membrane filtration is an effective water recycling and purification technology to remove various pollutants in water. Inorganic membrane filtration (IMF) technology has received widespread attention because of its unique high temperature and corrosion resistance. Commonly used inorganic membranes include ceramic membranes and carbon-based membranes. As novel catalytic inorganic membrane processes, IMF coupled with advanced oxidation processes (AOPs), can realize the separation and in situ degradation of pollutants, thus mitigating membrane contamination. In this paper, the types and performance of IMF are discussed. The influencing factors of inorganic membranes in practical wastewater treatment are summarized. The applications, advantages, and disadvantages of the coupled process of IMF and AOPs are summarized and outlined. Finally, the challenges and prospects of IMF and IMF coupled with AOPs are presented, respectively. This contributes to the design and development of coupled systems of membrane filtration with inorganic materials and IMF coupled with AOPs for practical wastewater treatment.

Strategies for Removing Endocrine Disrupting Chemicals (EDCs) from Wastewater.

Endocrine-disrupting drugs, also called endocrine disruptors or micropollutants, cause serious environmental and public health problems due to their ability to disrupt the endocrine functions of organisms and humans, even at low concentrations. This report provides a summary of current removal techniques, such as activated sludge processes, membrane filtration, adsorption, and membrane bioreactor techniques for endocrine-disrupting chemicals, including their efficiency, limitations, and practical implementation. This review evaluates these methods by considering their treatment efficiency, costs, and environmental impact. To curb this menace, several developed countries have distinct strategies, such as physical remediation techniques, biological processes, phytoremediation, and chemical processes to remove endocrine disruptors. In developing nations, most conventional wastewater treatment plants do not even monitor those contaminants due to the low biodegradability and high complexity of such compounds. Hence, in this review work, potential endocrine-disrupting chemicals, their impacts, mechanisms of action, consequences for human health, and bio-mitigation strategies reported so far have been discussed in the context of the relevant literature.

Comparative performance of electronegative membrane filtration and automated concentrating pipette for detection of antibiotic resistance genes and microbial markers in river water samples

The target viral and bacterial concentrations in river water are essential for environmental monitoring and public health studies. Filtration-based methods are commonly employed, yet challenges arise due to recoverability and filter pore size. This study aimed to compare the performance of electronegative membrane filtration (EMF) and automated Concentrating Pipette (CP) Select (InnovaPrep) methods for quantifying antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacterial and viral markers in river water samples. Fifty-four river water samples were collected from upstream and downstream locations in a river in Japan. The CP Select method was modified by adding MgCl2 and using different tips. The recovery efficiencies for total coliforms and Escherichia coli were assessed, and class 1 integron-integrase gene (intI1), 16S rRNA, gene encoding sulfonamide resistance (sul1), cross-assembly phage (crAssphage), pepper mild mottle virus (PMMoV), and Escherichia coli gene (sfmD) were detected. CP Select showed recovery efficiencies of 45 %–63 % for total coliforms and 17 %–35 % for E. coli. The intI1, 16S rRNA, sul1, crAssphage, PMMoV, and sfmD concentrations using the modified CP Select method were 10.1 ± 0.5, 8.7 ± 0.2, 7.7 ± 0.2, 6.7 ± 0.2, 5.4 ± 0.2, and 3.5 ± 0.5 log10 copies/L, respectively. Higher intI1 and sul1 concentrations were observed downstream, with the highest contribution percentage (22 % and 21 %) using CP Select or EMF. The modified CP Select method with 0.05 μm tips yielded more quantifiable results for all target genes and greater PMMoV concentrations (p < 0.05). Positive correlations were found among bacterial, ARG/MGE, and viral markers (Spearman's ρ = 0.71 for 16S rRNA and sfmD, 0.88 for intI1 and sul1, and 0.64 for PMMoV and crAssphage). The modified CP Select method demonstrated effective recovery of bacteria and quantification of ARGs, MGEs, and microbial markers in river water. Further studies are required to validate these methods and confirm their applicability in diverse environmental contexts.

A high-flux, photocatalytic wood-derived filter for high-efficiency water purification

Wastewater purification has evolved into a global problem in the face of increasing scarcity of freshwater resources. Photocatalysis technology possesses prominent advantages in treating pollutants in water because of its low cost and mild reaction conditions, which provides an effective way to treat multiple pollutants and reduce membrane fouling. Herein, we combine photocatalysis technology with filtration technology via in situ reduction Bi0 with Bi2SiO5 strategy incorporating a carbonized wood filter to synthesize carbon/Bi2SiO5@Bi bi-functional composite. Thus, simultaneous filtration and photocatalytic degradation of Rhodamine B and tetracycline were achieved. After filtrating for 30 min, the degradation rate of RhB and TC were 94.23 % and 81.39 %, respectively. Especially, the flux of RhB and TC were up to 2162.16 L m−2 h−1 and 1811.32 L m−2 h−1. In addition, the composite filter also has good recyclability and reusability, after 5 cycles, the degradation efficiency of RhB remains at 91 %. This study utilized photocatalytic technology combined with membrane filtration technology to successfully solve the contradiction between catalytic efficiency and water flux, which realized rapid and dynamic removal of organic pollutants from water. Besides, the use of carbonized wood-based materials provides a potential biomass technology for the preparation of bifunctional photocatalytic filters.

Design of a high-performance polyaniline coated niobium dicarbide MXene nanostructure based electro-membrane system for improved nanoplastic separation

This study explores the development of advanced electro-membrane filtration by incorporating Nb-based MXene (Nb2CTx) to enhance nanoplastic (NP) separation and fouling mitigation. The presence of NPs in water results in less effective filtration, hence increasing cost, highlighting the urgent need for advanced removal technologies. Nb2CTx was incorporated at varying loadings, revealing significant alterations in their morphological, structural, and physiochemical properties. The performance evaluation using NP-rich suspensions demonstrated that the membrane with 5 % Nb2CTx loading (MS5) achieved a NP removal efficiency of 97.4 % and a water flux of 90.5 L.m−2.h−1, which was significantly higher than the pristine sulfonated polyether sulfone (SPES) membrane (18.9 L.m−2.h−1 with 94 % removal efficiency). The membrane was developed for an electro-membrane system using a sacrificial anode. The sacrificial anode allowed for multiple complex process to occur simultaneously, including electrocoagulation and membrane filtration. Polyaniline (PANI) coating was added to further increase the conductivity to allow for a more energy efficient process. The study underscores the importance of Nb2CTx loading and PANI modification in improving the filtration efficiency and fouling resistance. Furthermore, applied electric field resulted in enhanced operational sustainability of SPES membranes, offering a novel approach for water treatment applications.

In the Depths of Wash Water: Isolation of Opportunistic Bacteria from Fresh-Cut Processing Plants.

The fruit and vegetable industry in post-harvest processing plants is characterized by a substantial consumption of water resources. Wash waters may serve as an environment for the periodic or permanent habitation of microorganisms, particularly if biofilm forms on the inner walls of tanks and flushing channels. Despite the implementation of integrated food safety monitoring systems in numerous countries, foodborne pathogens remain a global public health and food safety concern, particularly for minimally processed food products such as vegetables and fruits. This necessitates the importance of studies that will explore wash water quality to safeguard minimally processed food against foodborne pathogen contamination. Therefore, the current study aimed to isolate and identify bacteria contaminating the wash waters of four fresh-cut processing plants (Poland) and to evaluate the phenotypic antibiotic resistance profiles in selected species. Bacteria were isolated using membrane filtration and identified through mass spectrometry, followed by antibiotic susceptibility testing according to EUCAST guidelines. The results revealed that the level of contamination with total aerobic bacteria in the water ranged from 1.30 × 106 cfu/mL to 2.54 × 108 cfu/mL. Among the isolates, opportunistic pathogens including Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella oxytoca, Klebsiella pneumoniae, Serratia marcescens, and Proteus vulgaris strains were identified. An especially noteworthy result was the identification of cefepime-resistant K. oxytoca isolates. These findings highlight the importance of monitoring the microbial microflora in minimally processed foods and the need for appropriate sanitary control procedures to minimize the risk of pathogen contamination, ensuring that products remain safe and of high quality throughout the supply chain.

Dynamic behavior and mechanistic analysis in filtration of dilute particulate suspensions through nanofibrous membrane

Nanofibrous membranes have garnered significant interest in membrane filtration due to their high porosity, small pore sizes, and complex interconnected pore structures. Although many studies focus on size exclusion in surface filtration, the filtration behavior and mechanisms for particles smaller than the pore size have been relatively underexplored. In this study, membrane filtration using nanofibrous membranes was employed to elucidate the filtration behavior and mechanisms for polystyrene latex suspensions with particles smaller than the pore size. The results indicated that reducing fiber diameter decreases the pore size and enhances particle rejection, with particle retention occurring within the intricate three-dimensional nanofiber pore network. In contrast, the effect of the membrane’s basis weight was less significant compared to fiber diameter. This observation can be attributed to the concept of effective thickness; once this thickness is exceeded, particles are prevented from penetrating deeper into the membrane. The filtration model was analyzed using Hermans-Bredée blockage filtration theory and cake filtration theory, considering the mass of trapped particles within the membranes. The model characterizes the filtration process as initially following standard blocking, progressing to cake filtration once a sufficient number of pores become clogged.

Advanced Treatment: Tackling Paracetamol with Fenton Oxidation and Membrane Hybrid Processes

Paracetamol (PCT) in aquatic environments has become a global concern due to its potential harm to humans and environments. However, conventional water treatment was only able to degrade PCT partially. It was necessary to treat PCT contaminated water with tertiary technologies in particular by combination approach, such as Fenton oxidation and membrane filtration process. This combined approach enabling mitigation of large chemical footprint and iron residue associated with Fenton oxidation, as well as reducing fouling tendency of the membrane. The aim of this study was to evaluate the PCT removal efficiency by hybrid technology Fenton oxidation and membrane filtration. The membrane performance during the filtration process was also analyzed. As an important parameter for Fenton process, concentration of H 2 O 2 /Fe 2+ with ratio of 1:0.5 resulted in optimal removal of 45% PCT in terms of COD removal. However, separation using flat sheet Polyethersulfone Ultrafiltration (UF) with constant flux of 120 L/m²·h resulted in insignificant of COD removal. Nevertheless, the UF process was able to remove up to 54% of Fe 2+ at pH in alkaline condition with 8.5. In addition, a decrease in membrane permeability down to 0.2 L/m²h/bar over time, according to the filtered specific volume during the UF process, indicates fouling of the UF membrane during the 120 minutes of filtration. While the combined approach does not show significant improvement in COD removal, it does help to reduce the chemical footprint of the process, which is an important factor for the applicability of the selected water treatment method.

Exploring the emulsifying properties of biopolymers from Ulva lactuca in stabilizing high internal phase emulsions

Seaweed is a promising raw material for food emulsion stabilizers due to its abundance, low cost, and rich content of various natural biological macromolecules. This study explores the potential of using Ulva lactuca (UL) to stabilize emulsions by employing high-pressure homogenization (HPH) to release its interfacial active components. The results demonstrate that UL extract (ULE) with emulsifying activity was gradually extracted as the HPH pressure increased from 100 to 800 MPa. Concentrating the macromolecular components, specifically polysaccharides and proteins, in the ULE via membrane filtration resulted in a concentrated fraction, referred to as ULER, which exhibited enhanced emulsification performance. By optimizing the oil volume fraction (φ) and pH, it was found that high internal phase emulsions (φ = 0.7–0.8) showed superior viscoelasticity and stability at pH 3–7. In terms of stability, it was observed that the emulsions stabilized by ULER maintained their structure over extended periods without significant phase separation. The strong interaction between exogenous Ca2⁺ and ULER increased the apparent viscosity and viscoelasticity of the emulsion. However, the addition of Ca2⁺ did not significantly enhance the stability of the ULER-stabilized emulsions and, in some cases, even led to a decrease in emulsion stability. This effect may be probably due to the specific interactions between the Ca2⁺ ions and the polysaccharides and proteins in the ULER, which can affect the network structure of the emulsion. Overall, this study highlights the potential of HPH treatment in processing UL to transform it into an effective emulsion stabilizer for applications in the food industry.

Novel B4C supports for ceramic membrane filtration

Novel complex-shaped porous B4C supports were fabricated for use in ceramic membrane filtration applications, the processing of which is described in detail. Firstly, an extrudable ceramic paste was formulated and homogenised, containing a high content of B4C of super-coarse and ultrafine grades, plus water as liquid medium and various organic additives as thickener, binder, plasticiser, and lubricant. Secondly, tubular honeycomb parts (i.e., cylinders of ∼26 mm outer diameter with 30 inner channels of 3 mm diameter each) were extruded at ∼25 bar and dried in air at 120 °C for 24 h, resulting in robust green B4C membrane supports without macro- or micro-defects. Thirdly, suitable debinding conditions were identified by thermogravimetry of the paste and its components, and the dry membrane supports were debinded at 700 °C for 1.5 h in high vacuum (<0.1 Pa) confirming that they retain their shape with minimal isotropic shrinkage (∼0.13–0.15 %). And fourthly, the debinded membrane supports were pressureless sintered at 2000 °C for 3 h in inert atmosphere undergoing only an additional 1 % isotropic shrinkage, resulting in B4C membrane supports with low apparent density (∼0.89(1) g/cm3), high porosity (∼38–39 %), open interconnected micrometre pores (in the range ∼0.5–16 μm, and d50∼1.5 μm), and low skeletal density (∼2.455(1) g/cm3). Importantly, their only partial densification makes them both sufficiently strong mechanically (∼68(2) MPa compressive strength) and highly permeable to water (∼13131(418) l/(m2·h·bar) permeability at ∼1.3 bar). These attributes, together with the intrinsic lightness and durability of B4C ceramics, make these novel supports in principle very appealing for ceramic membrane filtration and other applications.