Porous Polymer Beads Research Articles

Cold-chain free nucleic acid preservation using porous super-absorbent polymer (PSAP) beads to facilitate wastewater surveillance

The instability of viral targets including SARS-CoV-2 in sewage is an important challenge in wastewater monitoring projects. The unrecognized interruptions in the ‘cold-chain’ transport from the sample collection to RNA quantification in the laboratory may undermine the accurate quantification of the virus. In this study, bovine serum albumin (BSA)-modified porous superabsorbent polymer (PSAP) beads were applied to absorb raw sewage samples as a simple method for viral RNA preservation. The preservation efficiency for SARS-CoV-2 and pepper mild mottle virus (PMMoV) RNA were examined during storage for 14 days at 4 °C or room temperature against the control (no beads applied). While a non-significant difference was observed at 4 °C (∼80 % retention for both control and PSAP-treated sewage), the reduction of SARS-CoV-2 RNA concentrations was significantly lower in sewage retrieved from PSAP beads (25–40 % reduction) compared to control (>60 % reduction) at room temperature. On the other hand, the recovery of PMMoV, known for its high persistence in raw sewage, from PSAP beads or controls were consistently above 85 %, regardless of the storage temperature. Our results demonstrate the applicability of PSAP beads to wastewater-based epidemiology (WBE) projects for preservation of SARS-CoV-2 RNA in sewage, especially in remote settings with no refrigeration capabilities.

Porous polymer beads with grafted poly(tertiary amine) as catalysts for fixation of carbon dioxide into propylene carbonate

Porous polymer beads with grafted poly(tertiary amine) as catalysts for fixation of carbon dioxide into propylene carbonate

Theory-driven design of phosphazene-based porous polymer beads for enhanced iodine adsorption

Efficient adsorbents for radioiodine removal play a crucial role in safeguarding public and ecology health. However, conventional trial-and-error approaches for designing such high-performance adsorbents suffer from limited efficiencies. Herein, we employed a rational design strategy guided by precise density functional theory (DFT) calculations to synthesize a polyphosphazene-based microsphere tailored for iodine capture. Theoretical calculations quantifying the interactions of iodine molecules with diverse nitrogen-containing organic groups reveal the superior affinity of phosphazene groups with I2. Motivated by these findings, we judiciously designed a poly(bis(diethylamino)) phosphazene (PDEP) with a high density of active adsorption sites. Subsequently, PDEP was integrated into a composite bead with polyether sulfone (denote as PDEP@PES) for practical applications. PDEP@PES exhibits an elevated static adsorption capacity of 1.08 g/g, surpassing the majority of reported beads. More importantly, under a high flow rate of 200 mL/min, the dynamic uptake amount of PDEP@PES reaches 78.8 mg/g, outperforming pristine PES beads (3.19 mg/g) and commercial silver-impregnated silica gel (23.0 mg/g). The XPS results confirm the formation of robust charge-transfer complex between phosphazene groups with I2. This was further supported by their substantial interaction energy of -20.59 kcal/mol, as determined by DFT calculations. Our study demonstrates the high feasibility of polyphosphazene-based microspheres for radioiodine removal, shedding light on the enormous potential of theory-driven design paradigm for the development of exceptional adsorbents for environmental remediation.

Highly Porous Polymer Beads Coated with Nanometer-Thick Metal Oxide Films for Photocatalytic Oxidation of Bisphenol A.

Highly porous metal oxide-polymer nanocomposites are attracting considerable interest due to their unique structural and functional features. A porous polymer matrix brings properties such as high porosity and permeability, while the metal oxide phase adds functionality. For the metal oxide phase to perform its function, it must be fully accessible, and this is possible only at the pore surface, but functioning surfaces require controlled engineering, which remains a challenge. Here, highly porous nanocomposite beads based on thin metal oxide nanocoatings and polymerized high internal phase emulsions (polyHIPEs) are demonstrated. By leveraging the unique properties of polyHIPEs, i.e., a three-dimensional (3D) interconnected network of macropores, and high-precision of the atomic-layer-deposition technique (ALD), we were able to homogeneously coat the entire surface of the pores in polyHIPE beads with TiO2-, ZnO-, and Al2O3-based nanocoatings. Parameters such as nanocoating thickness, growth per cycle (GPC), and metal oxide (MO) composition were systematically controlled by varying the number of deposition cycles and dosing time under specific process conditions. The combination of polyHIPE structure and ALD technique proved advantageous, as MO-nanocoatings with thicknesses between 11 ± 3 and 40 ± 9 nm for TiO2 or 31 ± 6 and 74 ± 28 nm for ZnO and Al2O3, respectively, were successfully fabricated. It has been shown that the number of ALD cycles affects both the thickness and crystallinity of the MO nanocoatings. Finally, the potential of ALD-derived TiO2-polyHIPE beads in photocatalytic oxidation of an aqueous bisphenol A (BPA) solution was demonstrated. The beads exhibited about five times higher activity than nanocomposite beads prepared by the conventional (Pickering) method. Such ALD-derived polyHIPE nanocomposites could find wide application in nanotechnology, sensor development, or catalysis.

Cytokines Removal During Ex-Vivo Lung Perfusion: Initial Clinical Experience.

Ex Vivo Lung Perfusion (EVLP) can be potentially used to manipulate organs and to achieve a proper reconditioning process. During EVLP pro-inflammatory cytokines have been shown to accumulate in perfusate over time and their production is correlated with poor outcomes of the graft. Aim of the present study is to investigate the feasibility and safety of cytokine adsorption during EVLP. From July 2011 to March 2020, 54 EVLP procedures have been carried out, 21 grafts treated with an adsorption system and 33 without. Comparing the grafts perfused during EVLP with or without cytokine adsorption, the use of a filter significantly decreased the levels of IL10 and GCSFat the end of the procedure. Among the 38 transplanted patients, the adsorption group experienced a significant decreased IL6, IL10, MCP1 and GCSF concentrations and deltas compared to the no-adsorption group, with a lower in-hospital mortality (p = 0.03) and 1-year death rate (p = 0.01). This interventional study is the first human experience suggesting the safety and efficacy of a porous polymer beads adsorption device in reducing the level of inflammatory mediators during EVLP. Clinical impact of cytokines reduction during EVLP must be evaluated in further studies.

Micrometre‐Sized Porous Polymer Beads as Heterogeneous Molecular Catalysts

AbstractPorous polymers have great potential as versatile, chemically stable catalyst supports. Yet, shaping of the resulting powders remains a challenge. Here, we demonstrate the use of suspension polymerisation to design micrometre‐sized porous polymers beads containing metal binding sites. The good accessibility of the binding sites ensures high catalytic activity, which is demonstrated for two model reactions: photochemical CO2 reduction and transfer hydrogenation of aromatic ketones. Importantly, the shaping of the host material does not affect the catalytic activity of the active site.

Virus Stabilization with Enhanced Porous Superabsorbent Polymer (PSAP) Beads for Diagnostics and Surveillance

Virus Stabilization with Enhanced Porous Superabsorbent Polymer (PSAP) Beads for Diagnostics and Surveillance

Removal of Apixaban during Emergency Cardiac Surgery Using Hemoadsorption with a Porous Polymer Bead Sorbent.

Background: Patients on direct oral anticoagulants are at high risk of perioperative bleeding complications. We analyzed the results of intraoperative hemoadsorption (HA) in patients undergoing cardiac surgery who were also on concurrent therapy with apixaban. Methods: we included 25 consecutive patients on apixaban who underwent cardiac surgery with the use of cardio-pulmonary bypass (CPB) at three sites. The first 12 patients underwent surgery without hemoadsorption (controls), while the next 13 consecutive patients were operated with the Cytosorb® (Princeton, NJ, USA) device integrated into the CPB circuit (HA group). The primary outcome was perioperative bleeding assessed by the Bleeding Academic Research Consortium (BARC) definition and secondary outcomes included 24 h chest-tube-drainage (CTD) and need for 1-deamino-8-d-arginine-vasopressin (desmopressin (DDAVP)) administration to achieve hemostasis. Results: Preoperative mean daily dose of apixaban was higher in the HA group (8.5 ± 2.4 vs. 5.6 ± 2.2 mg, p = 0.005), while time since last apixaban dose was longer in the controls (1.3 ± 0.9 vs. 0.6 ± 1.2 days, p < 0.001). No BARC-4 bleeding events and no repeat-thoracotomies occurred in the HA group compared with 3 and 1, respectively, in the controls. Postoperative 24 h CTD volume was significantly lower in the HA group (510 ± 152 vs. 893 ± 579 mL, p = 0.03) and there was no need for DDAVP compared to controls, who received an average of 10 ± 13.6 mg (p = 0.01). Conclusions: In patients on apixaban undergoing emergent cardiac surgery, the intraoperative use of hemoadsorption was feasible and safe. Compared to patients operated on without hemoadsorption, BARC-4 bleeding complications did not occur and the need for 24 h CTD and DDAVP was significantly lower.

Multi-ionic interaction with magnesium doped hydroxyapatite-zeolite nanocomposite porous polyacrylonitrile polymer bead in aqueous solution and spiked groundwater

Removal of multi-ionic contaminants from water resources has been a major challenge faced during the treatment of water for drinking and industrial applications. In the present study, varying composition of magnesium doped hydroxyapatite (Mg-HAp) and zeolite nanocomposite embedded porous polymeric beads were synthesized using solvent displacement method and its sorption efficiency towards multi-ion contaminant (such as Ag, Al, As, Ba, Be, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, Tl, Th, U, V and Zn) was investigated in aqueous solution and spiked groundwater. The prepared beads were characterized using suitable techniques like high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) equation. The surface area and pore radius of the beads varied from 6.996 to 66.469 m2/g and 1.698–3.960 nm respectively according to the composition of the bead. The control bead without nanocomposite showed maximum surface area. Multi-ion adsorptions onto beads were confirmed using an inductively coupled plasma-optical emission spectrophotometer (ICP-OES) and X-ray photoelectron spectrophotometer (XPS). The sorption efficiency was high at pH 5 owing to its anionic surface charge leading to an increase in affinity towards the cations. For validating field application, selected high performance beads were tested in multi-ion spiked groundwater. The results indicated that the Mg-HAp nanocomposite bead dominate all the other bead compositions with more than 90% removal efficiency for most of the multi-ion contaminants. The feasible adsorption mechanism has been discussed. This adsorption study revealed that the Mg-HAp nanocomposite bead is a promising material that is cost-effective, non-toxic, biodegradable, eco-friendly and highly efficient towards the removal of multi-ionic contaminants from groundwater.

Antithrombotic drug removal from whole blood using Haemoadsorption with a porous polymer bead sorbent.

To evaluate the ability of the DrugSorb™-AntiThrombotic Removal (ATR) haemoadsorption device utilizing porous polymer bead sorbent technology to remove three commonly used antithrombotic drugs from whole blood. We evaluated the removal of apixaban, rivaroxaban, and ticagrelor by the DrugSorb-ATR haemoadsorption device in a benchtop clinical scale model using bovine whole blood. Blood spiked at clinically relevant concentrations of an antithrombotic agent was continuously circulated through a 300-mL DrugSorb-ATR haemoadsorption device at a flow rate of 300mL/min. Drug concentration was monitored over 6h to evaluate drug removal. Results were compared with a control circuit without the haemoadsorption device. Removal rates at 30, 60, 120, and 360 minutes were: apixaban: 81.5%, 96.3%, 99.3% >99.8%; rivaroxaban: 80.7%, 95.1%, 98.9%, >99.5%; ticagrelor: 62.5%; 75%, 86.6%, >95% (all P<0.0001 vs. control). Blood pH and haematological parameters were not significantly affected by the DrugSorb-ATR haemoadsorption device when compared with the control circuit. DrugSorb-ATR efficiently removes apixaban, rivaroxaban, and ticagrelor in a clinical-scale benchtop recirculation circuit with the bulk of removal occurring in the first 60 minutes. The clinical implications of these findings are currently investigated in patients undergoing on-pump cardiothoracic surgery in two US pivotal trials (ClinicalTrials.gov Identifiers: NCT04976530 and NCT05093504).

Pitch-based porous polymer beads for highly efficient iodine capture

The efficient and safe capture of volatile radioiodine is of great significance in the reprocessing of spent fuel. Herein, the millimeter-scale pitch-based hyper-cross-linked porous polymers@polyethersulfone (PHCP@PES) composite beads were firstly synthesized for the removal of volatile iodine and methyl iodide. PHCP@PES beads exhibit high iodine vapor and methyl iodide uptake capacities of 770.0 mg/g and 186.5 mg/g, respectively. More impressively, the uptake capacities of PHCP@PES (744.5 mg/g for iodine vapor and 180 mg/g for methyl iodide) remained almost unchanged after treatment with 3 mol/L of nitric acid. The rich interconnected pore structure of PHCP@PES promotes the rapid physical capture of iodine and methyl iodide. Intrinsic features such as low-cost preparation, good mechanical properties as well as thermal, acid stability and excellent performance in iodine capture indicate that PHCP@PES can be used as a potential candidate for the removal of radioactive iodine in the exhaust gas stream of post-treatment plants.

Anchoring nanosized MOFs at the interface of porous millimeter beads and their enhanced adsorption mechanism for VOCs

Simultaneously exposure of adsorption sites and shortening the transmission paths of target adsorbate are crucial for developing advanced adsorbents. In this work, an in-situ phase inversion-hydrothermal (PIH) method is reported to achieve the anchoring of nanosized metal organic frameworks (MOFs) at the interface of porous polymeric beads. Especially, ligand of MIL-101 was loaded in polyethersulfone (PES) beads via phase inversion process. Followed by hydrothermal process, nanosized MIL-101 was prepared in confined space and immobilized on the interface of PES Beads. The resultant MIL-101@PES Beads could provide shorter transmission paths and more exposed active sites, which avoid the blockage of pore structure in traditional embedded method. Removal of typical volatile organic compounds (VOCs), i.e., benzene-containing oil-and-gas, was chosen to present the adsorption performance of MIL-101@PES Beads. From the dynamic adsorption results, excellent removal ability and reusability were observed on the adsorbents. Beads-3 obtained under moderate feeding ratio presented superior adsorption capacity (245.56 mg/g for benzene and 228.82 mg/g for n-hexane) in mono-component adsorption with 2.52 times transport kinetics (intraparticle mass transfer coefficient of 2.09 s−1) compared with embedded samples. These results demonstrated that MIL-101@PES Beads with shaped morphology and internal nanosized MOFs could serve as adsorbents in removing oil-and-gas. This work provides a novel protocol for the facile synthesis of shaped nanosized MOFs with enhanced performance for VOCs removal.

An approach for the scalable production of macroporous polymer beads

A tubular co-flow reactor to produce macroporous polymer beads by polymerization of medium and high internal phase emulsion (M/HIPE) templates was developed. This reactor allows for improved production rates compared to tubing based microfluidic devices. Water-in-oil (W/O) M/HIPEs, containing methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) monomers in the continuous phase, were injected into a re-circulating carrier phase. The continuous phase of the emulsion droplets was UV polymerized in situ, resulting in polyM/HIPE beads. The emulsion composition was adjusted to produce poly(MMA-co-EGDMA) porous polymer beads with a protective crust and an interconnected internal pore structure. HCl loaded beads were produced by adding the active ingredient into the dispersed emulsion phase, leading to HCl encapsulation in the porous structure of the beads after polymerization. Even after exposure to ambient conditions for 24 h, 60% of the HCl remained in the beads, indicating good encapsulation efficiencies. Thus, it is possible to use such macroporous beads as delivery vehicles.

Microalgae Harvesting by Self-Driven 3D Microfiltration with Rationally Designed Porous Superabsorbent Polymer (PSAP) Beads.

Microalgae are emerging as next-generation renewable resources for production of sustainable biofuels and high-value bioproducts. Conventional microalgae harvesting methods including centrifugation, filtration, flocculation, and flotation are limited by intensive energy consumption, high capital cost, long treatment time, or the requirement of chemical addition. In this study, we design and fabricate porous superabsorbent polymer (PSAP) beads for self-driven 3D microfiltration of microalgal cultures. The PSAP beads can swell fast in a microalgal suspension with high water absorption capacity. During this process, microalgal cells are excluded outside the beads and successfully concentrated in the residual medium. After treatment, the beads can be easily separated from the microalgal concentrate and reused after dewatering. In one PSAP treatment, a high concentration factor for microalgal cultures up to 13 times can be achieved in 30 min with a harvesting efficiency higher than 90%. Furthermore, microalgal cultures could be concentrated from 0.2 g L-1 to higher than 120 g L-1 with minimal biomass loss through multistage PSAP treatments. Therefore, the use of PSAP beads for microalgae harvesting is fast, effective, and scalable. It does not require any complex instrument or chemical addition. This technique potentially provides an efficient and feasible alternative to obtain high concentrations of functional biomass at a very low cost.

Self-Driven Pretreatment and Room-Temperature Storage of Water Samples for Virus Detection Using Enhanced Porous Superabsorbent Polymer Beads.

The continuous emergence of infectious viral diseases has become a major threat to public health. To quantify viruses, proper handling of water samples is required to ensure the accuracy and reliability of the testing results. In this study, we develop enhanced porous superabsorbent polymer (PSAP) beads to pretreat and store water samples for virus detection. By applying PSAP beads to collect water samples, the viruses are captured and encapsulated inside the beads while undesired components are excluded. We have successfully demonstrated that the shelf life of the model virus can be effectively extended at room temperature (22 °C) and an elevated temperature (35 °C). Both the infectivity level and genome abundance of the viruses are preserved even in a complex medium such as untreated wastewater. Under the tested conditions, the viral degradation rate constant can be reduced to more than 10 times using the PSAP beads. Therefore, the enhanced PSAP beads provide a low-cost and efficient sample pretreatment and storage method that is feasible and practical for large-scale surveillance of viral pathogens in water samples.

Highly Porous Poly(arylene cyano-vinylene) Beads Derived through the Knoevenagel Condensation of the Oil-in-Oil-in-Oil Double Emulsion Templates.

Conjugated porous polymers through the emulsion-templating polymerization process are typically prepared as monoliths, and the emulsions are cured via metal-catalyzed cross-coupling reactions. Herein, we report the design and synthesis of well-defined, millimeter-sized conjugated porous polymer beads by combining an oil-in-oil-in-oil (O/O/O) double emulsion as a de novo template and an amino-catalyzed Knoevenagel condensation reaction as a polymerization chemistry to cure such emulsions. The 1,4-phenylenediacetonitrile is reacted with aromatic multialdehydes in the presence of piperidine, and a series of metal-free poly(arylene cyano-vinylene) beads are prepared. All beads exhibit 3D-interconnected microcellular morphology and substantial semiconducting properties, such as strong light harvesting ability in the visible light region with electrochemical band gaps in the range of 2.05-2.33 eV. Finally, the promising photocatalytic activity of these conjugated beads is demonstrated for a model sulfoxidation reaction under visible light irradiation, and near quantitative conversions with excellent chemoselectivities (>99%) are obtained.

Biogas upgrading to fuel grade methane using pressure swing adsorption: Parametric sensitivity analysis on an industrial scale

Biogas upgrading to fuel-grade methane employing PSA technology is examined using a one-dimensional binary mixture comprising of CH4 and CO2, heat and mass balance model through Aspen Adsorption TM version 10 and Aspen Hysys simulation. Comparison between the experimental data over a bed of silica gel and the simulated results reveal that the methane and carbon dioxide breakthrough curves and temperature responses at various positions along the adsorption bed is in a good agreement. The effects of design parameters such as feed flowrate, adsorption step duration, axial dispersion coefficient, and bed dimensions at an industrial scale on methane purity and recovery are analyzed. Aside from silica gel, five more adsorbents including CMS-3 k, zeolite-NAUSY, Zeolite KZ10-04, porous polymeric beads and zeolite 5A were employed and their process performances were evaluated. CMS-3 K records the highest biomethane purity and recovery of 97.165% and 86.2%, respectively which meets the biogas quality standards. The developed model has great competence for making prediction of biogas upgrading performance of PSA cycle with impressive ability to manage the effect of heat generated on adsorption properties.

Construction of Porous Polymer Beads for CO2 Capture in a Fluidized Bed with High Stability

Construction of Porous Polymer Beads for CO₂ Capture in a Fluidized Bed with High Stability

Efficient removal of apixaban with extracorporeal hemoadsorption

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): CytoSorbents Medical Incorporation Background A hemadsorption device containing biocompatible porous polymer beads is easily incorporated into extracorporeal circuits including cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), continuous renal replacement therapy (CRRT), and hemoperfusion. This device has been shown to safely and effectively remove the P2Y12 receptor antagonist ticagrelor and the direct oral anticoagulant (DOAC) rivaroxaban during CPB in patients undergoing emergent cardiac surgery. Importantly, drug removal was associated with significant reductions in surgical bleeding and improved clinical outcomes resulting in CE Mark approval. Apixaban, another DOAC, has gained increasing popularity given its proven efficacy and lower risk of bleeding in clinical use. However, a pressing unmet medical need exists for the mitigation of the bleeding risk encountered in patients on apixaban who require urgent or emergent surgery. Currently approved reversal agents are only indicated in the case of uncontrolled or life-threatening bleeding, but not as preventive measures to mitigate surgical bleeding. Purpose To demonstrate the ability of the extracorporeal hemoadsorption device to remove apixaban from whole blood. Methods The hemoadsorption device was evaluated for removal of apixaban in an in vitro benchtop model using bovine whole blood. The 4L of blood were continuously circulated through a 300 mL porous polymer device over 6 hours at a flow rate of 300 mL/min to evaluate the drug removal kinetics of apixaban. Starting apixaban concentration of 300ng/mL was utilized in the model to reflect standard therapeutic levels. Plasma levels of apixaban over time were measured using liquid chromatography with tandem mass spectrometry (LC-MS-MS). A control setup utilized an identical flow circuit, minus the hemoadsorption device. Results Mean plasma concentration of apixaban was reduced to ∼9.1 ng/mL (equivalent to ∼96.3% removal) over the first 60 min of hemoperfusion with the device. Specifically, mean percent remaining plasma concentration of apixaban following device treatment was 42.2%, 18.6%, 8% and 3.7% after 15, 30, 45 and 60 min of therapy, respectively. Overall, ∼99.7% blood concentration of apixaban was removed over the total 6 h. Drug concentrations remained unchanged in the control circuit, with a statistically significant difference between the control and treatment groups at all time points except 0 h (p &amp;lt; 0.01). Conclusion Apixaban is efficiently removed with hemoadsorption using porous polymer device technology. Drug concentrations were reduced &amp;gt;96% after 60 min. Similarly, efficient benchtop removal utilizing the same technology was observed for ticagrelor and rivaroxaban, and subsequently translated into significant clinical benefit in patients requiring emergent cardiac surgery. The results of the current study hold significant promise for the future clinical applicability of apixaban removal. Abstract Figure. Percent of remaining apixaban over time

Photocatalytic quorum quenching: A new antifouling and in-situ membrane cleaning strategy for an external membrane bioreactor coupled to UASB

Microbial quorum sensing (QS) induces biofilm formation on the membrane surfaces leading to severe biofouling, which remains a major bottleneck for membrane-based systems. Here, we report an effective UV photocatalytic quorum quenching (QQ) strategy in an integrated upflow anaerobic sludge blanket – photocatalytic membrane reactor (UASB-PMR) system, where TiO2 nanoparticles immobilized in porous polymeric beads were kept in suspension as the photocatalysts. The UASB unit reached a methane yield of 0.30 ± 0.05 L CH4/g COD removal while treating the synthetic wastewater, slightly higher than a typical internal anaerobic membrane bioreactor (AnMBR). This novel system showed 7-fold higher efficacy in membrane fouling control than the UV photolytic QQ system (19.1 ± 2.4 d vs. 2.7 ± 1.0 d) under intermittent UV irradiation (17% of total operation time). Continuous UV irradiation, both in photolytic and photocatalytic QQ, significantly alleviated membrane biofouling, while long-term UV exposure exerted some changes in the surface properties of the membranes, which were not observed under intermittent UV irradiation. The reactive oxygen species (ROS) generated by the UV-excited TiO2 not only oxidized the foulants on the membrane surface, but also quenched acyl-homoserine lactones (AHLs), the QS signal molecules, thus retarding membrane fouling to the maximum extent. Additionally, in-situ membrane cleaning, enhanced COD removal, and almost complete disinfection of the effluent were realized in the photocatalytic QQ system. Equipped with these advantages, this innovative photocatalytic QQ can be a readily implementable strategy to prevent fouling in external membrane bioreactors (MBRs) for the pilot- and/or full-scale applications.