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In recent years, TiO 2 NPs have attracted great attention among the semiconductors because of stability, commercial availability, and ease of preparation. For this reason, NPs are widely used in wastewater treatment and membrane bioreactor (MBRs) In this study, the effect of titanium dioxide (TiO2) nanoparticle material was investigated on both the landfill leachate (LFL) treatment and membrane fouling performance. The system performance was evaluated for under varying TiO 2 concentrations (50–300 mg/L TiO 2), constant HRT (24 h), and constant backwashing (5 min)-relaxing (0.5 min) in AnMBR. The optimum conditions were determined as 300 mg/L TiO 2 and the corresponding to COD, Color, TOC and TN removal efficiencies were observed as 55 %, 23 %, 22 %, 30 %, respectively. The best membrane performance was observed at 300 mg/L TiO 2 corresponding to membrane fouling rate as 0.01 mbar/min. TiO 2 addition significantly mitigated membrane fouling (75 % decrease) for AnMBR. Bacteroidetes, Firmicutes and Proteobacteria have been observed to be the dominant species in LFL and MBRs. The bacterial species responsible for membrane fouling were determined as Alphaproteobacteria, Sphingobacteria and Flavobacteria. The addition of TiO 2 was determined membrane fouling decreased in AnMBR. As a result of TiO 2 NPs were observed to thin the cake layer and postpone membrane fouling and filtration. [Display omitted] • The best membrane performances were observed at 300 mg TiO 2 /L. • Membrane fouling rate was determined as 0.01 mbar/min. • TiO 2 addition significantly mitigated membrane fouling (75 % decrease). • TiO 2 prevents cake layer formation and/or pore clogging and postpone. • Bacteroidetes, Firmicutes and Proteobacteria have been observed as dominant species. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of electrocoagulation integrated in a laboratory-scale membrane bioreactor (MBR), namely EC-MBR, on the treatment performance, activated sludge morphological characterization, and membrane fouling of MBR treating actual sunflower oil refinery wastewater. The EC-MBR system exhibited significantly higher chemical oxygen demand (COD) and oil and grease (O&G) removal efficiency compared to the MBR system. Additionally, both systems achieved excellent turbidity removal, with a percentage above 99%. The membrane fouling rate was higher in the EC-MBR system compared to the MBR system. Despite the decrease in the soluble microbial product (SMP) and extracellular polymeric substance (EPS) concentration in the EC-MBR system, especially their protein fraction, the significant increase in MLSS and carbohydrates/protein ratio, and the decrease in the mixed liquor and the cake layer particles size were the main membrane fouling factors. The membrane fouling resistance distribution showed that the EC-MBR system had a higher percentage of pore blocking resistance compared to the MBR. FTIR analysis identified a greater proportion of carbohydrate compounds in the cake layer of the EC-MBR system. SEM images revealed dense microbial clusters, mainly rod- and oval-shaped bacteria, in the EC-MBR system. Furthermore, EDX analysis detected elements such as Ca, K, O, Al, and P in both systems, with the EC-MBR system showing a higher Al content. The EC-MBR system showed low energy consumption (0.431 kWh m−3) and total operating costs ($0.90 m−3), showcasing its effectiveness and affordability for sustainable wastewater management. [ABSTRACT FROM AUTHOR]

Traditional Chinese medicine (TCM) is often composed of a variety of natural medicines. Its composition is complex, and many of its components can not be analyzed and identified. The first step in the rational application of TCM is to successfully separate the effective components which is also a great inspiration for the development of new drugs. Among the many separation technologies of TCM, the traditional heating concentration separation technology has high energy consumption and low efficiency. As a new separation technology, membrane separation technology has the characteristics of simple operation, high efficiency, environment-friendly and so on. The separation effect of high molecular weight difference solution is better. The applications of several main membrane separation technologies such as microfiltration, nanofiltration, ultrafiltration and reverse osmosis are reviewed, the methods of restoring membrane flux after membrane fouling are discussed, and their large-scale industrial applications in the future are prospected and summarized. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Membrane fouling caused by effluent organic matter (EfOM) limits its further application in wastewater reuse. In this study, the effect of UV/chlorine pretreatment on membrane fouling was investigated in treating secondary effluent by ultrafiltration (UF) process. The relation between organic matter changes and fouling alleviation after UV/chlorine pretreatment was also studied according to the molecular weight (MW) changes in various resin fractions derived from EfOM. Results showed that UV/chlorine pretreatment effectively alleviated irreversible fouling, whereas chlorine pre-oxidation primarily mitigated reversible fouling. UV/chlorine pre-oxidation reduced 18% of reversible membrane fouling and 38% of irreversible membrane fouling at a chlorine dosage of 8 mg/L, indicating better performance in membrane fouling mitigation than chlorine pre-oxidation. UV/chlorine pre-oxidation also decreased dissolved organic matter in the UF permeate. The hydrophobic acidic (HPO-A) fraction caused dominant membrane fouling, while the hydrophilic (HPI) fraction contained most of high MW organic matter. Pre-oxidation changed the polarity of organic matter in the HPO-A fraction and decomposed the organics of high MW in the HPI fraction, which alleviated membrane fouling. These results showed that UV/chlorine pre-oxidation was a prospective pretreatment process prior to UF in wastewater reclamation. [ABSTRACT FROM AUTHOR]

In this research, silver/graphene oxide (Ag/GO) nanohybrid was first synthesized and used in production of polysulfone (PSF) ultrafiltration (UF) membranes via phase inversion method for concentrating phycocyanin (PC) and treating methylene blue (MB) dye effluent. Designing the experiment (DOE) using Box-Behnken method by Design Expert software helped to calculate the optimal values of the variables under study. The studied variables included PSF polymer concentration, polyvinyl pyrrolidone (PVP) pore-former concentration and Ag/GO nanohybrid content, which were investigated for their effects on pure water flux (PWF) and MB pigment rejection. According to the results of the DOE, the membrane containing 19.485 wt% PSF, 0.043 wt% PVP and 0.987 wt% Ag/GO was selected as the optimal membrane. Due to the high price of PC as drug, and the importance of removing MB pigment from the effluent of dyeing and textile industries, the membranes were first optimized with MB pigment and then the optimal membrane was used for concentrating PC. The results showed that PWF reaches from 40.05 L.m− 2.h− 1 (LMH) for the neat membrane to 156.73 LMH for the optimized membrane, which shows about 4 times improvement. Compared to the neat membrane, flux recovery ratio (FRR) of the optimized membrane increased by about 20% and its total fouling (Rt) decreased by about 10%. Also, the results showed that the optimized membrane can remove 81.6% of MB, as well as to reject 93.8% of PC. [ABSTRACT FROM AUTHOR]

Membrane fouling caused by many direct and indirect triggering factors has become an obstacle to the application of membrane bioreactors (MBRs). The nonlinear relationship between those factors is subject to complex causality or affiliation, which is difficult to clarify for the diagnosis of membrane fouling. To solve this problem, this paper proposes a compressible diagnosis model (CDM) based on transfer entropy to facilitate the fault diagnosis of the root cause for membrane fouling. The novelty of this model includes the following points: Firstly, a framework of a CDM between membrane fouling and causal variables is built based on a feature extraction algorithm and mechanism analysis. The framework can identify fault transfer scenarios following the changes in operating conditions. Secondly, the fault transfer topology of a CDM based on transfer entropy is constructed to describe the causal relationship between variables dynamically. Thirdly, an information compressible strategy is designed to simplify the fault transfer topology. This strategy can eliminate the repetitious affiliation relationship, which contributes to diagnosing the root causal variables speedily and accurately. Finally, the effectiveness of the proposed CDM is verified by the measured data from an actual MBR. The results of experiments demonstrate that the proposed CDM fulfills the diagnosis of membrane fouling. [ABSTRACT FROM AUTHOR]

This study explored using ultrafiltration (UF) membranes to treat pulp and paper mill wastewater, implementing a novel Taguchi experimental design to optimize operating conditions for pollutant removal and minimal membrane fouling. Researchers examined four factors: pH, temperature, transmembrane pressure, and volume reduction factor (VRF), each at three levels. Optimal conditions (pH 10, 25°C, 6 bar, VRF 3) led to a 35% reduction in flux due to fouling and high pollutant rejections: total hardness (83%), sulfate (97%), spectral absorption coefficient (SAC254) (95%), and chemical oxygen demand (COD) (89%). Conductivity had a lower rejection rate of 50%. Advanced imaging techniques like atomic force microscopy (AFM) and scanning electron microscopy (SEM) revealed reduced membrane fouling under these conditions. The Taguchi method effectively identified optimal conditions, significantly improving wastewater treatment efficiency and promoting environmental sustainability in the pulp and paper industry. Practitioner Points: This study optimized UF membrane conditions for pulp and paper mill wastewater, reducing fouling and enhancing pollutant removal, offering practical strategies for industrial treatment.AFM and SEM provided key insights into membrane fouling and mitigation, promoting real‐time diagnosis and optimization for enhanced treatment efficiency.Prioritizing anaerobic fixed‐bed systems in wastewater treatment is beneficial for achieving high COD removal efficiency. Optimizing hydraulic retention time (HRT) in these systems can further improve their overall effectiveness and sustainability. [ABSTRACT FROM AUTHOR]

This experimental study explores the mitigation of membrane fouling in membrane bioreactors (MBRs) through the combined use of granular activated carbon (GAC) and powdered activated carbon (PAC). The research assesses the impact of these materials on the fouling resistance, critical flux, and permeate quality using various mixed liquor suspended solids concentrations and carbon dosages. The results indicate that the GAC-PAC combination significantly reduces the total filtration resistance, particularly the cake layer resistance, by 11.7% to 13.6% compared to setups without activated carbon or with the individual carbon types. The study also reveals that this combination decreased the fouling rate by 15% to 24% at critical flux steps, demonstrating substantial improvements in fouling mitigation and operational efficiency. Furthermore, the GAC-PAC combination, which produces an adsorption process, enhances the permeate quality, achieving the near-complete removal of organic matter, total nitrogen, and turbidity, with total phosphorus removal reaching 99%. These findings demonstrate that the combined use of GAC and PAC not only reduces membrane fouling but also improves the overall MBR performance, making it a viable strategy for enhancing the efficiency of wastewater treatment processes. [ABSTRACT FROM AUTHOR]

In this study, aniline-containing wastewater was treated using the microbial flora present in activated sludge and a membrane separation system reactor. A swing-type membrane bioreactor (S-MBR) system with swinging membrane components was designed to control membrane fouling during reactor operation. Furthermore, the new system was tested and compared with the aerated membrane bioreactor (A-MBR) and the common membrane bioreactor (C-MBR). The study revealed the following findings: 1) S-MBR exhibited a high aniline removal rate, with an efficiency of 97% in removing aniline from wastewater with a concentration of 600 mg/L. 2) S-MBR demonstrated a high membrane flux, reaching a maximum of 97 L/m2 h bar, whereas C-MBR and A-MBR achieved 49 L/m2 h bar and 87 L/m2 h bar, respectively. 3) S-MBR proved to be energy-efficient, with lower energy consumption during aniline removal (0.032 kW/kg C6H7N) compared to C-MBR (0.051 kW/kg C6H7N) and A-MBR (0.039 kW/kg C6H7N). These observations suggest that the S-MBR system designed in this study is comparatively more effective, feasible, and economical. [ABSTRACT FROM AUTHOR]

Considering the serious water crisis in the world and the use of saltwater resources of the seas and oceans as available water resources, desalination technology for these waters is to be raised in all societies of the world. Due to the protection and increasing efficiency of desalination methods, the design of a suitable pretreatment method for desalination of salt water has made the process more economic. The methodology used in this research for the analysis of technological schemes includes two groups of technological and economic indicators: (A) water quality data and (B) economic characteristics of the processes. The study is based on a set of experimental projections of water quality data after pretreatments, such as turbidity and the SDI15 (silt density index) index. These data were received from several full-scale systems and full-scale plants. These plants are (1) conventional pretreatment, (2) MF (microfilter) pretreatment, and (3) UF (ultrafilter) pretreatment method. The average SDI15 index of filtrate during the study time provided by the UF and MF systems was 1.5 and 2.9, respectively. The daily decay of permeability by UF and MF systems was 0.86% and 0.45%, respectively. The total cost of the produced water (including investment and O&M) for the conventional treatment full-scale plant, the pretreatment based on the MF membrane, and the UF membrane were obtained at approximately 0.42, 0.46, and 0.55euro/m3 of produced water. Membrane-based pretreatment is a competitive technological alternative to conventional methods. [ABSTRACT FROM AUTHOR]

The growing demand for biological therapeutics has increased interest in large‐volume perfusion bioreactors, but the operation and scalability of perfusion membranes remain a challenge. This study evaluates perfusion cell culture performance and monoclonal antibody (mAb) productivity at various membrane fluxes (1.5–5 LMH), utilizing polyvinylidene difluoride (PVDF), polyethersulfone (PES), or polysulfone (PS) membranes in tangential flow filtration mode. At low flux, culture with PVDF membrane maintained higher cell culture growth, permeate titer (1.06–1.34 g/L) and sieving coefficients (≥83%) but showed lower permeate volumetric throughput and higher transmembrane pressure (TMP) (>1.50 psi) in the later part of the run compared to cultures with PES and PS membrane. However, as permeate flux increased, the total mass of product decreased by around 30% for cultures with PVDF membrane, while it remained consistent with PES and PS membrane, and at the highest flux studied, PES membrane generated 12% more product than PVDF membrane. This highlights that membrane selection for large‐volume perfusion bioreactors depends on the productivity and permeate flux required. Since operating large‐volume perfusion bioreactors at low flux would require several cell retention devices and a complex setup, PVDF membranes are suitable for low‐volume operations at low fluxes whereas PES membranes can be a desirable alternative for large‐volume higher demand products at higher fluxes. [ABSTRACT FROM AUTHOR]

Abstract In this research, silver/graphene oxide (Ag/GO) nanohybrid was first synthesized and used in production of polysulfone (PSF) ultrafiltration (UF) membranes via phase inversion method for concentrating phycocyanin (PC) and treating methylene blue (MB) dye effluent. Designing the experiment (DOE) using Box-Behnken method by Design Expert software helped to calculate the optimal values of the variables under study. The studied variables included PSF polymer concentration, polyvinyl pyrrolidone (PVP) pore-former concentration and Ag/GO nanohybrid content, which were investigated for their effects on pure water flux (PWF) and MB pigment rejection. According to the results of the DOE, the membrane containing 19.485 wt% PSF, 0.043 wt% PVP and 0.987 wt% Ag/GO was selected as the optimal membrane. Due to the high price of PC as drug, and the importance of removing MB pigment from the effluent of dyeing and textile industries, the membranes were first optimized with MB pigment and then the optimal membrane was used for concentrating PC. The results showed that PWF reaches from 40.05 L.m− 2.h− 1 (LMH) for the neat membrane to 156.73 LMH for the optimized membrane, which shows about 4 times improvement. Compared to the neat membrane, flux recovery ratio (FRR) of the optimized membrane increased by about 20% and its total fouling (Rt) decreased by about 10%. Also, the results showed that the optimized membrane can remove 81.6% of MB, as well as to reject 93.8% of PC.

Simultaneous nitrification and denitrification (SND) is an efficient method to remove nitrogen in municipal wastewater treatment. However, low dissolved oxygen (DO) concentrations are generally required, leading to serious membrane fouling in membrane bioreactors (MBRs). This study aimed to clarify the synergistic effect of biomass and DO on nitrogen removal and membrane fouling. To achieve this goal, four submerged MBRs equipped with ceramic membranes were operated with different biomass (mixed liquor suspended solids (MLSS)) concentrations (3 000 mg/L, 5 000 mg/L, 7 500 mg/L, and 12 000 mg/L) under various DO concentrations (2.0 mg/L, 1.0 mg/L, and 0.5 mg/L). As a result, increasing biomass in the MBRs enhanced total nitrogen (TN) removal via SND, and excellent TN removal efficiencies of 60.7% and 75.8% were obtained using the MBR with an MLSS concentration of 12 000 mg/L and DO concentrations of 2.0 mg/L and 1.0 mg/L. However, a further decrease in DO deteriorated TN removal due to the inhibition of nitrification. Moreover, high MLSS concentrations were beneficial to membrane fouling control for ceramic membranes in MBRs. The lowest transmembrane pressure development rate was observed for the MBR with an MLSS concentration of 12 000 mg/L. High biomass offset the adverse effect of DO decrease on membrane fouling to some extent, and improved the stability of the reactor. Therefore, biomass might be an important parameter for membrane fouling reduction in ceramic MBRs. Overall, optimal biomass and DO concentrations for TN removal were identified, providing useful information for the successful operation of MBRs with efficient TN removal and membrane fouling control.

• High pH favored to form large and loose flocs for both coagulants though Al 13 flocs were more stable. • Large and loose flocs led to more porous cake and further generated lower reversible fouling. • In all pH conditions, Al 13 had higher HA removal than PACl due to higher removal of HA with lower MW. • Al 13 had low membrane fouling at acid pH and PACl favored to reduce membrane fouling at alkaline pH. Membrane fouling is a bottleneck issue that hindered the further application of ultrafiltration technology. To alleviate membrane fouling, coagulation-ultrafiltration (C-UF) process using polyaluminum chloride (PACl) and PACl-Al 13 with high proportion of Al 13 O 4 (OH) 24 7+ as coagulants, respectively, were investigated at various pH conditions. Results indicated that an increase in solution pH contributed to larger floc size and looser floc structure for both PACl and PACl-Al 13. It was conducive to the formation of more porous cake, as evidenced by mean pore area and pore area distribution of cake, leading to lower reversible fouling. Furthermore, humic acid (HA) removal presented a trend of first increasing and then decreasing with the increase of pH. The optimal HA removal was achieved at pH 6 regardless of coagulant type, suggesting that the slightest irreversible fouling should be occurred at this point. Interestingly, the irreversible fouling with PACl coagulant achieved a minimum value at pH 9, while the minimal irreversible fouling with PACl-Al 13 was observed at pH 6. We speculated that the cake formed by PACl could further intercept HA prior to UF process at alkaline pH. Furthermore, compared with PACl, PACl-Al 13 had a stronger charge neutralization ability, thus contributing to more compact floc structure and higher HA removal at various pH conditions. By UF fractionation measurement, higher HA removal for PACl-Al 13 was due to higher removal of HA with molecular weight less than 50 kDa. [Display omitted] [ABSTRACT FROM AUTHOR]

• Increasing periodic aeration rate reduced irreversible fouling of GDM. • Reclaimed wastewater was feasible for hydroponic vegetable cultivations. • Plants grown with treated water were comparable to those with fertilizer. • Shifting nutrient level and operation mode influenced plant growth profile. • Basil grown in reclaimed water had less health risk impact compared to lettuce. In this study, a gravity-driven membrane (GDM) filtration system and hydroponic system (cultivating basil and lettuce) were combined for nutrient recovery from primary municipal wastewater. The GDM system was optimized by increasing the periodic air sparging flow rate from 1 to 2 L/min (∼15 hr per 3–4 days), resulting in a ∼52% reduction of irreversible fouling. However, the total fouling was not alleviated, and the water productivity remained comparable. The GDM-filtrated water was then delivered to hydroponic systems, and the effects of hydroponic operation conditions on plant growth and heavy metal uptake were evaluated, with fertilizer- and tap water-based hydroponic systems and soil cultivation system (with tap water) for comparison. It was found that (i) the hydroponic system under batch mode facilitated to promote vegetable growth with higher nutrient uptake rates compared to that under flow-through feed mode; (ii) a shift in nutrient levels in the hydroponic system could impact plant growth (such as plant height and leaf length), especially in the early stages. Nevertheless, the plants cultivated with the GDM-treated water had comparable growth profiles to those with commercial fertilizer or in soils. Furthermore, the targeted hazard quotient levels of all heavy metals for the plants in the hydroponic system with the treated water were greatly lower than those with the commercial fertilizer. Especially, compared to the lettuce, the basil had a lower heavy metal uptake capability and displayed a negligible impact on long-term human health risk, when the treated water was employed for the hydroponic system. [Display omitted] [ABSTRACT FROM AUTHOR]

This study examines the impact of incorporating a mobile bed into a membrane bioreactor (MBR) system on the treatment efficiency of dairy industry effluents. Initially, a conventional MBR system was operated for 60 days, followed by a modification that included a support material and ran for another 60 days under identical conditions. Performance was evaluated based on the removal efficiencies for soluble chemical oxygen demand (CODs), phenolic compounds, and oils and greases (OG), alongside measurements of solid content, dissolved oxygen, temperature, mixed liquor pH, and transmembrane pressure (TMP). The introduction of the mobile bed led to an increase in removal efficiencies for COD and phenolic compounds from 94.4 and 92.7% to 98 and 94.4%, respectively, marking statistically significant improvements (p < 0.05), while OG removal remained the same in both strategies (87.7%) (p > 0.05). Moreover, the modified system showed a more stable TMP profile, reducing the need for cleaning interventions compared to the conventional system, which experienced a notable TMP increase requiring cleaning at a 0.6 bar threshold. The findings suggest that integrating a mobile bed into MBR systems significantly enhances the treatment of dairy effluents, presenting an interesting solution for the upgrade of this type of system. HIGHLIGHTS The integration of a mobile bed into MBR systems significantly increases the removal efficiency of phenolic compounds.; Modified MBR systems with a mobile bed significantly reduce membrane fouling, making MBR operation more stable.; Integrating a mobile bed offers a promising upgrade for dairy effluent treatment.;

Ultrafiltration (UF) technology is an efficient shale gas flowback water treatment method. However, severe membrane fouling is the primary restriction on the application of UF technology. Here, we studied the impact of three pretreatments: precipitative softening (PS), precipitative softening, followed by ozonation (PS-O) and ozonation, followed by precipitative softening (O-PS), on pollutants' removal efficiencies and membrane fouling. The results showed that (1) the hardness, bacteria, scaling trend and compatibility with formation water exceeded the requirements for water reuse; (2) pretreatments effectively increased water flux and prolonged ultrafiltration membrane life, and both of them followed the order of PS-O process > O-PS process > PS process; (3) the fouling mechanism was changed from the complete blocking model to the standard blocking model by the PS process and the addition of ozonation enhanced the correlation of standard blocking model; (4) the quality of fracturing liquid prepared by the effluent treated by the PS-O-UF process was the best and satisfied the requirements of slick water. This paper indicated that the PS-O-UF process was suitable for the treatment of Changning shale gas flowback water for reuse. [ABSTRACT FROM AUTHOR]

Membrane surface fouling has always been a critical issue for the long-term operation of polymeric membranes. Therefore, it is crucial to develop new approaches to prevent fouling. While developing new approaches, characterization methods are greatly important for understanding the distribution of fouling on the membrane surface. In this work, a cellulose acetate membrane was fouled by the filtration of artificial wastewater based on alginate. The surfaces of fouled membranes were characterized through scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), and white light interferometry (WLI). The results were then compared in terms of the resolution, accuracy, feasibility, and cost-efficiency. [ABSTRACT FROM AUTHOR]

Potassium sodium niobates (KNNs) have garnered significant attention owing to their lead-free nature and potential for use in self-cleaning membranes. This paper presents the synthesis of (K 0.5 Na 0.5)NbO 3 materials for the fabrication of porous membranes, which enable in situ ultrasonic resonance to effectively eliminate contaminants from the membrane surface. KNN powder was synthesized via solid-state reactions, and the membranes were prepared using conventional sintering techniques. The effects of ball-milling time and calcination temperature on the phase structure, pore size, permeance, flexural strength, chemical stability, and piezoelectric properties were comprehensively investigated. The optimal membranes exhibited an average pore size of approximately 300 nm, a porosity of 23 %, and permeance of 220 L m−2 h−1 bar−1 at a sintering temperature of 1050 °C. A polarized electrical field with a strength of 1 kV/mm was applied to the membranes, resulting in an ultrasonic response of 20 mV at an excitation voltage of 20 V with a frequency of 200 kHz. Furthermore, the in situ anti-fouling performance was evaluated by conducting filtration tests on a 500 ppm oil-in-water (O/W) emulsion, demonstrating that the stationary flux increased by 46.7 % when subjected to an excitation voltage of 60 V. [ABSTRACT FROM AUTHOR]

Direct ultrafiltration (UF) is anticipated to be a promising technology for rural water supply due to its stable permeate quality and ease of automatic operation & maintenance. However, seasonal high turbidity in the surface water resources caused severe membrane fouling, resulting in the requirement of frequent cleaning of the UF process, and limiting the broad application of the direct UF in treating rural surface water. To address this issue, this study investigated the feasibility and mechanism of in situ aeration in alleviating the UF membrane fouling in treating surface water with high turbidity (200, 500, and 800 NTU). The results indicated that with the weak aeration (0.4 m3/(m2·min)), the concentration of polysaccharides accumulated on the membrane surface was high, and serious membrane fouling was observed. With medium aeration (0.8 and 1.2 m3/(m2·min)), bubble shear force could effectively reduce the foulants accumulated on the membrane surface to alleviate the membrane fouling. During the whole experiment, the optimal group (1.2 m3/(m2·min)) showed a 45% lower TMP compared to the control. However, strong aeration (1.6 m3/(m2·min)) caused floc breakage and was less conducive to the membrane fouling control compared to the medium aeration. Furthermore, under in situ aeration, the contents of polysaccharide accumulated on the membrane surface and deposited in the membrane pores were reduced by 8.85%~49.29%, and the structures of the cake layer turned out to be porous and permeable, implying that in situ aeration could significantly modify the structure and composition of the cake layer, contributing to the UF membrane fouling control in treating the seasonal high-turbidity surface water. These findings will provide novel approaches for the application of UF technology in rural water supply. [ABSTRACT FROM AUTHOR]

Membrane bioreactor (MBR) is a promising technology for the treatment of municipal and industrial wastewater, including highly contaminated textile wastewater. However, membrane fouling remains a critical challenge due to reduced flux. This study investigates the efficacy of a moving bed MBR (MB‐MBR) technology for textile wastewater treatment, focusing on chemical oxygen demand (COD) removal, and its impact on mitigating membrane fouling. In a 50‐day study, a conventional MBR (R1) was compared with an MB‐MBR (R2) augmented with free‐floating biocarriers (accounting for 20% of the reactor volume). Both systems used flat sheet ceramic membrane modules. The results indicate that the MB‐MBR achieved superior performance, with COD and colour removal of 89% and 81%, respectively, compared with 87% and 73% in the conventional MBR. Importantly, the introduction of biocarriers eliminated the need for offline physical membrane cleaning in the MB‐MBR. The free‐floating biocarriers lowered transmembrane pressure, reduced capillary suction time and reduced fouling through their scouring action. Highlights: A conventional MBR and moving bed‐MBR were compared in textile wastewater treatment.Almost equal COD removal efficiencies were found in both operations.Higher color removals were obtained by moving bed‐MBR process.The moving bed‐MBR reduced the TMP, CST of sludge and membrane fouling propensity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigated the effect of low DO operation on the performance of membrane bioreactors (MBRs) in treating wastewater with low carbon to nitrogen ratios(C/N = 3.5), the microbiological communities in them, and on membrane fouling. Two bench-scale MBRs were operated in tandem under different DO regimes: one maintained at an average DO of 0.5 mg/L and the other at 2 mg/L. Both systems exhibited high organic carbon removal efficiencies above 97%, with the low-DO reactor demonstrating a slight advantage. While the low DO conditions limited nitrification due to oxygen depletion affecting nitrifying bacteria, these conditions favored improved total nitrogen removal by achieving simultaneous nitrification and denitrification (SND) process. This improvement is attributed to the facilitation of denitrification and other nitrogen transformations, including the anammox and comammox pathways. Furthermore, the low DO environment was associated with reduced membrane fouling rates, suggesting that reduced aeration does not compromise membrane fouling mitigation. Microbial community analysis revealed that lower DO concentrations significantly increased diversity, as evidenced by alpha and beta diversity metrics. Redanduncy Analysis (RDA) confirmed the proliferation of nitrogen-transforming bacteria under low DO conditions, and the detection of anammox and comammox bacteria in the sludge samples confirmed the operation of these alternative nitrogen removal pathways. [ABSTRACT FROM AUTHOR]

Copyright of Technology of Water Treatment is the property of Technology of Water Treatment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Membrane fouling by monoclonal antibodies (mAbs) is one of the main challenges in virus‐filtration processes. Previous publications attributed membrane fouling to the presence of mAb aggregates in the solution, which block the membrane pores. This fouling mechanism can be solved by a prefilter; however, it was shown that there are mAbs that severely foul the membranes (reduce permeability by 90% and more) even after prefiltering the aggregates, while other mAbs foul the membrane weakly (reduce permeability by ~10% and less). Unfortunately, the differences between the fouling‐ and the nonfouling mAbs have never been convincingly explained. To get a deeper insight on these differences, we measured the fouling of chemically modified Isoprene‐Styrene‐4‐vinylpyridine (ISV) membranes (TeraPore Technologies) by 8 mAbs exhibiting different hydrophobicity and charge. The results show that mAb solutions with low concentration of aggregates foul ISV membranes via an adsorptive mechanism, and the adsorption is driven mainly by hydrophobic forces between the mAb and the membrane. The charge of the mAbs plays a secondary role in fouling. We want to emphasize that the conclusions pertain to ISV membranes; the insights presented in this paper can potentially be used to engineer new surface chemistries to mitigate fouling of other virus‐filtration and/or ultrafiltration membranes. [ABSTRACT FROM AUTHOR]

Membrane photobioreactors (MPBRs) have gained significant attention due to their ability to support microalgae activities such as cultivation, harvesting, and production of beneficial products. Despite various efforts to mitigate membrane fouling, a fundamental issue in membrane processes, in these systems, a cost-effective and less energy-consuming method is still needed. This study examines the impact of the cross-sectional area of the riser and the baffle material on membrane fouling in an internal loop airlift MPBR. The use of hydrophilic polyester-polypropylene (PES–PP) baffles proves to be more effective than plexiglass baffles. Specifically, in configurations with d = 0.7 cm and d = 1.4 cm, RC/RT decreased by approximately 20% and 13%, respectively, compared to plexiglass baffles. As for the values of RP/RT at a distance of d = 0.7, nearly a 5% increase was observed, and at a distance of d = 1.4, an increase of approximately 11% was observed. This is due to the development of the cake layer on the matrix structure of the PES–PP baffles instead of the membrane itself. The most optimal outcomes were reached while working with PES–PP at a distance of 0.7 cm, as it prolonged the membrane fouling time to 46 h. [ABSTRACT FROM AUTHOR]

Water scarcity poses significant challenges in arid regions like the Middle East and North Africa (MENA) due to constant population growth, considering the effects of climate change and water management aspects. The desalination technologies face problems like high energy consumption, high investment costs, and significant environmental impacts by brine discharge. This paper researches the relationships among water scarcity, energy-intensive desalination, and the development of renewable energy in MENA, with a particular focus on the Gulf Cooperation Council (GCC) countries. It examines innovations in solar-powered desalination, considering both solar photovoltaic (PV) and solar thermal technologies, in combination with traditional thermal desalination methods such as multi-effect distillation (MED) and multi-stage flash (MSF). The environmental impacts associated with desalination by brine discharge are also discussed, analyzing innovative technological solutions and avoidance strategies. Utilizing bibliometrics, this report provides a comprehensive analysis of scientific literature for the assessment of the research landscape in order to recognize trends in desalination technologies in the MENA region, providing valuable insights into emerging technologies and research priorities. Despite challenges such as high initial investment costs, technical complexities, and limited funding for research and development, the convergence of water scarcity and renewable energy presents significant opportunities for integrated desalination systems in GCC countries. Summarizing, this paper emphasizes the importance of interdisciplinary approaches and international collaboration by addressing the complex challenges of water scarcity and energy sustainability in the MENA region. By leveraging renewable energy sources and advancing desalination technologies, the region can achieve water security while mitigating environmental impacts and promoting economic development. [ABSTRACT FROM AUTHOR]

In the present study, improved treatment of synthetic wastewater using integrated electrochemical membrane bioreactor (EMBR) and the addition of graphene oxide nanoparticles (GO-NPs) is reported. For this aim, GO-NPs were reduced and modified using ethylene diamine (EDA). After that, EDA-treated GO particles (RGO-NH2) were exposed to alkylation, and repetitive amidation for synthesizing polyamidoamine (PAMAM)-bonded nanosheets of GO. The Fourier transform infrared (FTIR) results confirmed the formation of various structures, while thermogravimetric analysis (TGA) graphs showed the occurrence of non-ideal reactions and lack of PAMAM bonding as expected. Moreover, X-ray diffraction (XRD) graphs showed that the bonding resistance exists against the bonding of nanosheets. The results showed that GO-NPs included EMBR systems led to a significant reduction in membrane fouling, and operational time was extended for ca. 20 days before reaching the flux limit. This could be due to the reduction in the cake layer extracellular polymeric substances (EPS) fraction with a significant decrease in the content of protein-like compounds in the lightly bound EPS (LB-EPS) fraction. This could be related to the electrophilic attack of electro-generated OH· radicals to the electron-rich moieties of fouling agents, adsorption of organic fouling agents on the outer surface of GO-NPs, increase in overall sludge particle size and prevention of floc penetration through membrane pores. The results were validated by the FTIR and emission excitation matrix (EEM) spectroscopy methods. The results of the current study could be beneficial for the operation of a scaled-up system using more membrane modules and a larger permeate flowrate. [ABSTRACT FROM AUTHOR]

Ultrafiltration (UF) has been widely utilized as water pretreatment for different applications especially in water reuse. The UF system operation is characterized by a filtration phase, where particles accumulate on the membrane surface resulting in an increase in the transmembrane pressure (TMP) and a cleaning phase, where foulants are removed through cleaning cycles including physical backwash and chemical-enhanced backwash (CEB). In this study, data from an engineering-scale UF system treating reclaimed wastewater were used to assess the impact of backwashing on the filtration process. TMP backwash trigger, backwash duration, and CEB frequency were purposely varied for a cycle-by-cycle investigation on the net water production, water recovery, initial operating TMP, and filtration cycle duration. As the TMP backwash trigger was varied between 62 and 145 kPa, the maximum net water production (63 m3/d) was achieved at 103 kPa and water recovery remained relatively constant at approximately 92 %. Backwash durations of 45, 65, and 85 s were performed where both net water production and water recovery yielded similar results (~63 m3/d and ~ 91 %) compared with 103 kPa TMP backwash trigger. The CEB frequency was also lowered from one every three backwashes (1/3) to 1/6 and 1/12 and resulted in decreased net water production and water recovery while the initial TMP increased. Interestingly, the total number of CEBs remained approximately constant regardless of their frequency. Results suggest that CEB is an important fouling control process to maximize water production.

In practical applications, protein fouling studies often face limitations due to their reliance on single-protein feed experiments. It is crucial to acknowledge that interprotein interactions can significantly differ from intraprotein interactions, leading to variations in adsorption and membrane fouling behaviors. In this review, we delve into the dynamics of adsorption and membrane fouling, with a specific focus on single and binary solutions of Bovine Serum Albumin (BSA) and Lysozyme (LYZ) at or near physiological pH. These two proteins differ in terms of size, charge, and conformational stability, allowing for comparisons between small and large proteins, positively and negatively charged proteins, as well as rigid and flexible proteins. To gain further insights, we compare the findings from LYZ in single and binary solutions with those of alpha lactalbumin (α-LA), which, despite having opposite charges, shares a similar size with LYZ. The formation of BSA-LYZ heteroprotein complexes may introduce unique fouling trends in binary solutions compared to single solutions. This interplay can either enhance, reduce, or leave fouling unaffected. While studies employing the Extended DLVO (Derjaguin, Landau, Vervey, and Overbeek) theory to predict fouling in protein mixtures are limited, preliminary investigations using DLVO show promise. This approach has the potential to extend to binary and multi-protein feeds, providing valuable insights into the dynamics of fouling behavior in complex protein solutions. Considering that BSA is often used as a surrogate for Human Serum Albumin (HSA), the findings of this endeavor hold particular significance. HSA ranks the most abundant plasma proteins and, therefore, represents a crucial subject in numerous protein-related studies.

The S(IV)–Fe(II)/PM pretreatment has demonstrated preliminary potential as an effective ultrafiltration (UF) pretreatment technology. However, a comprehensive understanding of its impact on UF membrane fouling control and the dynamic evolution of membrane fouling during prolonged operation is still lacking. In this study, a relatively prolonged fouling experiment was conducted. Results revealed that the S(IV)–Fe(II)/PM pretreatment exhibited superior performance over Al(III) coagulation pretreatment in mitigating the transmembrane pressure difference and addressing both reversible and irreversible membrane fouling. The application of a cluster analysis method to classify membrane fouling evolution stages further confirmed that S(IV)–Fe(II)/PM pretreatment effectively decelerated the rate of membrane fouling evolution. The surface cake layer of UF membranes pretreated with S(IV)–Fe(II)/PM exhibited greater looseness and smoothness. It also showed better results than Al(III) coagulation pretreatment in reducing the accumulation of organic foulants, controlling the Si content and reducing the total microorganisms and live microorganisms in the UF feed water. Variance Partitioning Analysis indicated that the combined contribution of organic, inorganic, and biological foulants was the most significant for UF membranes after S(IV)–Fe(II)/PM pretreatment (50.4%) and UF membranes after Al(III) coagulation pretreatment (70.2%). These findings underscore the efficacy of S(IV)–Fe(II)/PM pretreatment in controlling UF membrane fouling under prolonged operation. HIGHLIGHTS S(IV)/Fe(II)/PM pretreatment efficiently mitigated UF membrane fouling during long-term operation.; S(IV)/Fe(II)/PM pretreatment yielded a long uncontaminated stage and accelerated contaminated stage.; S(IV)/Fe(II)/PM pretreatment suppressed the contribution of organic–inorganic–biological composite fouling.;

Membrane distillation is an energy-saving technology that utilizes low-grade energy to treat highly saline water, however, the current use of the technology is faced with serious membrane fouling, wetting and other problems. Conductive membranes have received attention in recent years for the ability of alleviating the problems of fouling, wetting and temperature polarization in membrane distillation under the influence of the electrostatic repulsion, electrochemical redox and Joule heating brought about by the applied electric field. The structure, principle and research progress of membrane distillation were summarized, with emphasis on introducing and comparing the structure, action mechanism and characteristics of capacitive mode, resistive mode and alternating current mode operation in membrane distillation. The capacitive mode mainly solved the fouling and wetting problems through electrostatic repulsion, electrochemical redox, and electrically induced bubbles, while the resistive mode created higher vapor pressure and pure water flux through higher voltage and reduced biofouling through Joule heating, and the alternating current mode prevented the formation of contamination through the exchange of polarity, which made the fouling layer loose. Finally, the treatment efficacy, anti-fouling efficacy, anti-wetting efficacy and anti-temperature polarization of the conductive membrane distillation were elaborated, providing a reference for the application and development of the conductive membrane distillation in engineering.

Optical monitoring technologies can be used to monitor membrane fouling in real-time and online with the in-situ, fast and nondestructive advantages, which are of great significance for the in-depth understanding of membrane fouling and the optimization of fouling control strategies. In this paper, several kinds of optical real-time monitoring technologies for membrane fouling that had been studied and developed rapidly in recent years were reviewed, including microscopic imaging techniques such as direct observation through membrane, optical coherence tomography and laser confocal microscopy, molecular spectroscopies such as excitation-emission matrix and Raman spectroscopy, and particle image velocimetry. The principles, the typical applications in fouling characterization of these techniques and the derivative techniques were described comprehensively, and the advantages and disadvantages of each technique were analyzed from the aspects of monitoring area and foulant information provided. Finally, the future development direction of the optical monitoring technologies was put forward, which would promote the application of these technologies in the membrane water treatment industries.

Abstract Patients in intensive care are exposed to the risk of microparticle infusion via extracorporeal lines and the resulting complications. A possible source of microparticle release could be the extracorporeal circuit used in blood purification techniques, such as continuous renal replacement therapy (CRRT). Disposable components of CRRT circuits, such as replacement bags and circuit tubing, might release microparticles such as salt crystals produced by precipitation in replacement bags and plastic microparticles produced by spallation. In-line filtration has proven effective in retaining microparticles both in in-vitro and in-vivo studies. In our study, we performed an in-vitro model of CRRT-treatment with the aim of detecting the microparticles produced and released into the circuit by means of a qualitative and quantitative analysis, after sampling the replacement and patient lines straddling a series of in-line filters. Working pressures and flows were monitored during the experiment. This study showed that microparticles are indeed produced and released into the CRRT circuit. The inclusion of in-line filters in the replacement lines allows to reduce the burden of microparticles infused into the bloodstream during extracorporeal treatments, reducing the concentration of microparticles from 14 mg/mL pre in-line filter to 11 mg/mL post in-line filter. Particle infusion and related damage must be counted among the pathophysiological mechanisms supporting iatrogenic damage due to artificial cross-talk between organs during CRRT applied to critically ill patients. This damage can be reduced by using in-line filters in the extracorporeal circuit.