Membrane-based Water Treatment Research Articles

New mechanistic insight into the microbial responses to on-line chemical cleaning of UF membranes with NaClO

On-line membrane cleaning with NaClO is frequently implemented during membrane-based water treatment, where diverse aqueous microorganisms inevitably react with NaClO, leading to a significant impact on the next-round operation. This study filled the knowledge gap to explore the respective response of bacteria, algae and fungi to NaClO exposure. The results indicated that the three types of microorganisms exhibited distinct behaviors to NaClO attack. Specifically, E. coli showed stronger adaptation to NaClO by releasing more EPS and agglomeration behavior to resist chemical attack, thereby maintaining a higher survival rate. In contrast, M. aeruginosa and Aspergillus might experience significant cell death caused by substantial production of ROS. During subsequent ultrafiltration, accelerated biofouling development with a thinner biofilm layer was found for all three microorganisms exposed to NaClO, especially for M. aeruginosa and Aspergillus who formed the biofilms with remarkable stratified structures. The biofilm formed by E. coli was strongly correlated with EPS secretion, while excessive production of ROS and attachment of survived cells on membrane were considered as crucial factors controlling the biofilm development for M. aeruginosa and Aspergillus. Detailed responding mechanisms to NaClO cleaning were eventually proposed for the respective three microorganisms, which offered new insight into UF system operation for water treatment.

2D/2D nanohybrid of MoS2/g-C3N4 engineered polysulfone (PSF) membrane with enhanced filtration and anti-fouling performance

The rational design of 2D hybrid materials has gained substantial attention in the field of membrane-based water treatment. In this study, a hierarchical flower-like MoS2/g-C3N4 (Hf-MoCN) hybrid has been reported as a modifier for antifouling and performance enhancement of polysulfone (PSF) membranes. PSF membranes modified with 0.1, 0.3, and 0.5 wt% of Hf-MoCN were prepared by phase inversion technique. The prepared membranes were examined for their morphology, contact angle, pore size, and porosity. Further, the ultrafiltration performance and antifouling ability of the PSF/ Hf-MoCN were examined through BSA filtration studies. The contact angle dropped from 78° to 55° when 0.3 wt% of Hf-MoCN was incorporated into the PSF matrix. Moreover, the pure water and BSA fluxes of this modified membrane were improved by 2.1 and 3.6 folds, respectively, compared to the bare membrane. Besides, all Hf-MoCN modified membranes showed higher BSA rejection efficiency than the unmodified membrane. Flux recovery ratio studies showed that the membrane modified with 0.3 wt% of Hf-MoCN had better antifouling ability than the other membranes. Thus, the study showed that the incorporation of Hf-MoCN provided the membrane with a versatile transport pathway and desirable surface properties, thus improving its wettability, filtration performance and antifouling ability.

A comprehensive review on the use of Ti3C2Tx MXene in membrane-based water treatment

Population growth, industrial activities, and the energy demands of water production intensify the global challenge of accessing clean water. Membrane-based water treatment processes have emerged as crucial solutions to address this crisis, these include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), forward osmosis (FO), reverse osmosis (RO), and membrane distillation (MD). This review summarizes the properties and use of Ti3C2Tx MXene, a material with notable chemical stability, specific surface area, hydrophilicity, thermal conductivity, and environmental compatibility. Ti3C2Tx fills in the class of two-dimensional materials, it is promising in various membrane processes by offering enhancement in hydrophilicity, permeability, and selectivity. In UF, Ti3C2Tx-based membranes have superior antifouling properties and high rejection rates of contaminants. Meanwhile, in NF, MXene nanosheets elevate the rejection of organics, dyes, and salts, and present valuable nanocomposite membranes. In desalination, incorporating Ti3C2Tx in RO membranes is found to increase water permeability while maintaining high salt rejection in desalination. Also, MXene-modified FO membranes had lower fouling and improved water flux compared with plain membranes, presenting a promising avenue for water purification. Additionally, Ti3C2Tx enhanced water vapor transport and resistance against wetting, which is favorable in MD.This review underscores the transformative potential of Ti3C2Tx MXene in revolutionizing membrane-based water treatment processes, providing innovative solutions to meet the escalating global demand for clean water. Future research directions should optimize MXene-based membrane designs and scale up their production for practical applications in water treatment, thereby contributing to a more sustainable water future.

Assessment of physical pre-treatments for the recovery of biosurfactants in corn steep water prior to advanced membrane-based water treatment

The aim of this work is to evaluate different physical pre-treatments for corn steep water (CSW) to obtain a cleaner, concentrated water stream in biosurfactants for further advanced water treatment, involving not only the decontamination of water but also the complete recycling of CSW. Three physical treatments were tested: i) decantation, ii) centrifugation, and iii) vacuum filtration under different temperatures. After these pre-treatments, several parameters were evaluated. Results showed that centrifugation at 4 °C (C4L) is the best alternative for concentrating biocompounds as it produced a cleaner stream with a greater lightness (from 0.45 to 92.9–96.2) and lower turbidity than decantation or vacuum filtration but with a higher content in biosurfactants. Moreover, it was observed that acidification of C4L produced a decrease in the surface tension properties of CSW compatible with the precipitation and/or denaturalization of lipopeptides and proteins, whereas basification did not produce any relevant effect. Acidification or basification during pre-treatment of CSW was therefore dismissed with the recommendation of performing a simple centrifugation step at 4 °C as a pre-treatment, prior to recovering bioactive compounds using advanced membrane water treatments.

Predicting forward osmosis performance with synthesized polyamide-based membrane: An integrated machine learning (MATLAB and ANN) and economic analysis framework

Forward Osmosis (FO) has emerged as a highly promising membrane-based water treatment process owing to its intrinsic advantages, such as low energy requirements and the potential for high water recovery. The lab-prepared highly efficient thin film composite (TFC) FO membranes that were used in this research work. The resultant polyamide-based FO membrane showed exceptional performance, notably achieving a high-water flux of 60.94 ± 3.5 L/m2.h and a constrained solute flux of 1.52 ± 0.08 g/m2.h. Machine learning methodologies are strategically employed in this study to construct predictive models for FO membrane performance. Notably, the accuracy of the van't Hoff equation's linear assumption is significantly enhanced by introducing an osmotic pressure calculation based on water activity, considering the nuanced effects of external and internal concentration polarization. The research employs MATLAB software alongside an artificial neural network (ANN) to develop predictive models. MATLAB facilitates the creation of a comprehensive theoretical model, offering insights into forecasting water flux through FO membranes by systematically analyzing diverse membrane parameters and their impact on performance. Concurrently, the ANN model was employed to predict the permeate flux for the laboratory-scale FO membrane system, utilizing the input parameters within the network's training range (R2 > 0.91). An economic assessment is also conducted to estimate the projected membrane cost, a pivotal determinant of system viability. Collectively, these investigations yield valuable insights into the intricacies of FO membrane design and optimization, elucidating their performance dynamics in water treatment and allied applications. This research significantly contributes to the ongoing quest to develop more efficient and precise membrane processes.

Antibiofouling polyethersulfone ultrafiltration membranes functionalized with MoS2 nanosheets and self-cleaning with hydrogen peroxide

The development of biofouling mitigation and cleaning strategy is of paramount importance for ultrafiltration (UF) membrane biofouling. In this study, polyethersulfone (PES) UF membrane was functionalized, namely MoS2/PES composite membrane. The MoS2/PES composite membrane exhibited superior antifouling property as evidenced by antibacterial circle, static and dynamic biofouling experiments. The permeate fluxes of the pristine PES and MoS2/PES composite membrane respectively decreased by 76% and 31% at the end of 3-h filtration. After exposure of E. coli to MoS2, inhibited cell growth led to reduced membrane biofouling. The biofilm formation was retarded under the dynamic flow condition, which were further confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) observations. As for the enhanced biofouling removal by cleaning with H2O2, 62% of the flux recovery rate for the MoS2/PES composite membrane was much higher than the pristine PES membrane (24%). The peroxidase-like properties of MoS2 were responsible for the enhancement of the superior cleaning performance. The use of H2O2 to trigger the in-situ catalytic function of the MoS2 nano-enzyme generated more ROS and O2 for inducing bacterial cells death and facilitating detachment of biofilm. This work will be helpful to provide important insights into developing more effective strategies for biofouling control and cleaning using advanced nanomaterials in membrane-based water treatment processes.

Poly(arylene ether)s-Based Polymeric Membranes Applied for Water Purification in Harsh Environment Conditions: A Mini-Review.

Confronting the pressing challenge of freshwater scarcity, polymeric membrane-based water treatment technology has emerged as an essential and effective approach. Poly(arylene ether)s (PAEs) polymers, a class of high-performance engineering thermoplastics, have garnered attention in recent decades as promising membrane materials for advanced water treatment approaches. The PAE-Based membranes are employed to resist the shortages of most common polymeric membranes, such as chemical instability, structural damage, membrane fouling, and shortened lifespan when deployed in harsh environments, owing to their excellent comprehensive performance. This article presents the advancements in the research of several typical PAEs, including poly(ether ether ketone) (PEEK), polyethersulfone (PES), and poly(arylene ether nitrile) (PEN). Techniques for membrane formation, modification strategies, and applications in water treatment have been reviewed. The applications encompass processes for oil/water separation, desalination, and wastewater treatment, which involve the removal of heavy metal ions, dyes, oils, and other organic pollutants. The commendable performance of these membranes has been summarized in terms of corrosion resistance, high-temperature resistance, anti-fouling properties, and durability in challenging environments. In addition, several recommendations for further research aimed at developing efficient and robust PAE-based membranes are proposed.

Inhibiting Biofilm Formation via Simultaneous Application of Nitric Oxide and Quorum Quenching Bacteria.

Membrane biofouling is an inevitable challenge in membrane-based water treatment systems such as membrane bioreactors. Recent studies have shown that biological approaches based on bacterial signaling can effectively control biofilm formation. Quorum quenching (QQ) is known to inhibit biofilm growth by disrupting quorum sensing (QS) signaling, while nitric oxide (NO) signaling helps to disperse biofilms. In this study, batch biofilm experiments were conducted to investigate the impact of simultaneously applying NO signaling and QQ for biofilm control using Pseudomonas aeruginosa PAO1 as a model microorganism. The NO treatment involved the injection of NONOates (NO donor compounds) into mature biofilms, while QQ was implemented by immobilizing QQ bacteria (Escherichia coli TOP10-AiiO or Rhodococcus sp. BH4) in alginate or polyvinyl alcohol/alginate beads to preserve the QQ activity. When QQ beads were applied together with (Z)-1-[N-(3-aminopropyl)-N-(n-propyl) amino]diazen-1-ium-1,2-diolate (PAPA NONOate), they achieved a 39.0% to 71.3% reduction in biofilm formation, which was substantially higher compared to their individual applications (16.0% to 54.4%). These findings highlight the significant potential of combining QQ and NO technologies for effective biofilm control across a variety of processes that require enhanced biofilm inhibition.

Zwitterionic polymer brush functionalized graphene oxide blended polyethersulfone membrane with enhanced performance and anti-biofouling properties

Biofouling still poses a significant challenge to membrane-based water treatment as it compromises water flux, increases energy consumption, and reduces membrane life. Zwitterion-based polymer brushes have recently received a great deal of attention as prospective anti-biofouling materials. This study explored the efficacy of grafting zwitterionic polymer brushes on Graphene oxide (GO) blended Poly-ether sulfone (PES) membrane to develop better-performing ultrafiltration (UF) membranes with enhanced anti-biofouling potential. These GO-blended PES membranes were modified by surface-initiated atom transfer radical polymerization (SI-ATRP) to graft poly[2-(methacryloyloxy) ethyl dimethyl-(3-sulfopropyl) ammonium hydroxide] (pMEDSAH) zwitterionic brushes to the membrane surface. The pMEDSAH grafting has improved the hydrophilicity and provided smoother topology to the surface. Compared to the pristine PES membrane, the pMEDSAH grafted GO-PES membrane (PES-GO-PB) showed better performance with an increase in water flux and improvement in BSA rejection. In dynamic biofouling experiments using Escherichia coli, ∼ 90% decrease in the live biomass for polymer brushes-modified membrane was observed. The water flux recovery has also been enhanced for the PES-GO-PB membrane. Finally, the relation between ATRP reaction time and membrane performance was also explored, and the result suggested that membrane porosity acts as a key factor.

Inhibiting Polyamide Intrusion of Thin Film Composite Membranes: Strategies and Environmental Implications.

Thin film composite polyamide (TFC) nanofiltration (NF) membranes represent extensive applications at the water-energy-environment nexus, which motivates unremitting efforts to explore membranes with higher performance. Intrusion of polyamide into substrate pores greatly restricts the overall membrane permeance because of the excessive hydraulic resistance, while the effective inhibition of intrusion remains technically challenging. Herein, we propose a synergetic regulation strategy of pore size and surface chemical composition of the substrate to optimize selective layer structure, achieving the inhibition of polyamide intrusion effective for the membrane separation performance enhancement. Although reducing the pore size of the substrate prevented polyamide intrusion at the intrapore, the membrane permeance was adversely affected due to the exacerbated "funnel effect". Optimizing the polyamide structure via surface chemical modification of the substrate, where reactive amino sites were in situ introduced by the ammonolysis of polyethersulfone substrate, allowed for maximum membrane permeance without reducing the substrate pore size. The optimal membrane exhibited excellent water permeance, ion selectivity, and emerging contaminants removal capability. The accurate optimization of selective layer is anticipated to provide a new avenue for the state-of-the-art membrane fabrication, which opens opportunities for promoting more efficient membrane-based water treatment applications.

NaHCO3 addition enhances water permeance and Ca/haloacetic acids selectivity of nanofiltration membranes for drinking water treatment

The existence of disinfection by-products such as haloacetic acids (HAAs) in drinking water severely threatens water safety and public health. Nanofiltration (NF) is a promising strategy to remove HAAs for clean water production. However, NF often possesses overhigh rejection of essential minerals such as calcium. Herein, we developed highly selective NF membranes with tailored surface charge and pore size for efficient rejection of HAAs and high passage of minerals. The NF membranes were fabricated through interfacial polymerization (IP) with NaHCO3 as an additive. The NaHCO3-tailored NF membranes exhibited high water permeance up to ∼24.0 L m − 2 h − 1 bar−1 (more than doubled compared with the control membrane) thanks to the formation of stripe-like features and enlarged pore size. Meanwhile, the tailored membranes showed enhanced negative charge, which benefitted their rejection of HAAs and passage of Ca and Mg. The higher rejection of HAAs (e.g., > 90%) with the lower rejection of minerals (e.g., < 30% for Ca) allowed the NF membranes to achieve higher minerals/HAAs selectivity, which was significantly higher than those of commercially available NF membranes. The simultaneously enhanced membrane performance and higher minerals/HAAs selectivity would greatly boost water production efficiency and water quality. Our findings provide a novel insight to tailor the minerals/micropollutants selectivity of NF membranes for highly selective separation in membrane-based water treatment.

A critical review on thermodynamic mechanisms of membrane fouling in membrane-based water treatment process

A critical review on thermodynamic mechanisms of membrane fouling in membrane-based water treatment process

Interface interaction between silica and organic macromolecule conditioned forward osmosis membranes: Insights into quantitative thermodynamics and dynamics

Silica scaling is a rising concern in forward osmosis membrane-based water treatment process. The coexistence of ubiquitous organic macromolecules causes complex silica scaling. The silica scaling mechanism on the surface of the organic conditioned membrane remains unclear. An integrated multi scale thermodynamic and dynamic approach was used in this study to provide in-depth insights into the binding effect at the interface between the silica and the organic conditioned membrane at the molecular level. Sodium alginate (SA) was used as the model polysaccharide, bovine serum albumin (BSA) and lysozyme (LYZ) were chosen as two oppositely charged proteins. The results show that the silica scaling degree of different organic conditioned membranes follows the order LYZ > BSA > SA. The binding strength between silica and organic macromolecules and the membrane surface charge are the major factors governing the degree of silica scaling. Quartz crystal microbalance with dissipation (QCM-D), isothermal titration calorimetry (ITC), and extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) model analyses were conducted to quantify the binding capacity of silica to the organic conditioned membrane. The LYZ conditioned membrane exhibits the highest affinity for silica adsorption, and electrostatic interaction was the main molecular interaction force. This study provides fresh insights into how silica and an organic conditioned membrane interact and induce silica scaling, providing new information on potential mechanisms and control strategies to prevent membrane scaling.

Membrane-based water and wastewater treatment technologies: Issues, current trends, challenges, and role in achieving sustainable development goals, and circular economy

Membrane-based technologies are recently being considered as effective methods for conventional water and wastewater remediation processes to achieve the increasing demands for clean water and minimize the negative environmental effects. Although there are numerous merits of such technologies, some major challenges like high capital and operating costs . This study first focuses on reporting the current membrane-based technologies, i.e., nanofiltration, ultrafiltration, microfiltration, and forward- and reverse-osmosis membranes. The second part of this study deeply discusses the contributions of membrane-based technologies in achieving the sustainable development goals (SDGs) stated by the United Nations (UNs) in 2015 followed by their role in the circular economy. In brief, the membrane based processes directly impact 15 out of 17 SDGs which are SDG1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16 and 17. However, the merits, challenges, efficiencies, operating conditions, and applications are considered as the basis for evaluating such technologies in sustainable development, circular economy, and future development.

Development of Functional Hybrid Polymers and Gel Materials for Sustainable Membrane-Based Water Treatment Technology: How to Combine Greener and Cleaner Approaches.

Water quality and disposability are among the main challenges that governments and societies will outside during the next years due to their close relationship to population growth and urbanization and their direct influence on the environment and socio-economic development. Potable water suitable for human consumption is a key resource that, unfortunately, is strongly limited by anthropogenic pollution and climate change. In this regard, new groups of compounds, referred to as emerging contaminants, represent a risk to human health and living species; they have already been identified in water bodies as a result of increased industrialization. Pesticides, cosmetics, personal care products, pharmaceuticals, organic dyes, and other man-made chemicals indispensable for modern society are among the emerging pollutants of difficult remediation by traditional methods of wastewater treatment. However, the majority of the currently used waste management and remediation techniques require significant amounts of energy and chemicals, which can themselves be sources of secondary pollution. Therefore, this review reported newly advanced, efficient, and sustainable techniques and approaches for water purification. In particular, new advancements in sustainable membrane-based filtration technologies are discussed, together with their modification through a rational safe-by-design to modulate their hydrophilicity, porosity, surface characteristics, and adsorption performances. Thus, their preparation by the use of biopolymer-based gels is described, as well as their blending with functional cross-linkers or nanofillers or by advanced and innovative approaches, such as electrospinning.

A review on UiO-66 applications in membrane-based water treatment processes

Metal-organic frameworks (MOFs) are a modern class of materials that got great academic attention over the last two decades. Recently, serious attempts were conscripted to scale up several types of them and involve industrial applications. UiO-66 is a zirconium-based MOF that was synthesized in 2008 and widely applied in many fields since then. As researchers investigated UiO-66 applications, this material continuously showed high performance and remarkable properties, which increased the interest for further exploitation. In water treatment, where many MOFs are utilized in various processes, UiO-66 is among the intensively applied ones mainly due to its high-water stability. However, the UiO-66's stability is not limited to water; it is stable in organics and acids, in addition to its high thermal stability. Moreover, UiO-66 has the general MOF properties of large surface area, proper pore diameter, large pore volume, functional surface, etc.In this review, we will focus on the use of UiO-66 in membrane-based water treatment processes. These processes include ultrafiltration, nanofiltration, forward osmosis, and reverse osmosis, which are used for dyes, heavy metals, proteins, and antibiotics removal, as well as desalination. Based on database information, UiO-66 use in water treatment is constantly increasing due to the promising opportunities this material raises. Here, it became necessary to explain the up-to-date progress in the membranes field and explore the available future aspects and aspirations of UiO-66.

Lamellar carbon nitride membrane for enhanced ion sieving and water desalination

Membrane-based water treatment processes offer possibility to alleviate the water scarcity dilemma in energy-efficient and sustainable ways, this has been exemplified in filtration membranes assembled from two-dimensional (2D) materials for water desalination purposes. Most representatives however tend to swell or disintegrate in a hydrated state, making precise ionic or molecular sieving a tough challenge. Here we report that the chemically robust 2D carbon nitride can be activated using aluminum polycations as pillars to modulate the interlayer spacing of the conjugated framework, the noncovalent interaction concomitantly affords a well-interlinked lamellar structure, to be carefully distinguished from random stacking patterns in conventional carbon nitride membranes. The conformally packed membrane is characterized by adaptive subnanochannel and structure integrity to allow excellent swelling resistance, and breaks permeability-selectivity trade-off limit in forward osmosis due to progressively regulated transport passage, achieving high salt rejection (>99.5%) and water flux (6 L m−2 h−1), along with tunable permeation behavior that enables water gating in acidic and alkaline environments. These findings position carbon nitride a rising building block to functionally expand the 2D membrane library for applications in water desalination and purification scenarios.

A comprehensive performance comparison on the impact of MOF-71, HNT, SiO2, and activated carbon nanomaterials in polyetherimide membranes for treating oil-in-water contaminants

The effective treatment of industrial oil/water emulsion before discharging into the receiving bodies is essential to prevent environmental pollution and its negative impacts on human health. The nanomaterial-incorporated nanocomposite membranes are touted as suitable candidates for removing oil contaminants from water. The selection of nanomaterial in nanocomposite membranes is crucial to fit the intended application. In this study, the performance of four different nanomaterials, i.e., metal-organic frameworks-71 (MOF-71), silicon dioxide (SiO2), activated carbon (AC), and halloysite nanotubes (HNTs), were used as the nanofiller of membranes. The resultant membranes were characterized by FESEM, AFM, water contact angle, and FTIR analysis. The membrane performance was examined in pure water flux (PWF) and oil/water emulsion rejection studies. The enhancement of PWF in SiO2, HNTs, MOF-71, and AC-based PEI/PVP composite membranes compared to neat PEI/PVP membranes was 33.33%, 59.25%, 70.37%, and 77.77%, respectively. The PEI/PVP/MOF-71 and PEI/PVP/AC membranes exhibited the best performance for PWF and oil/water rejection. Engine oil/water, hexane/water, and toluene/water % rejection of PEI/PVP/AC membrane was found to be 91.98%, 90.55%, and 93.74%, respectively, significantly higher than the neat PEI/PVP membrane. Furthermore, the nanomaterials-incorporated membrane showed better antifouling properties than the neat PEI/PVP membrane due to enhanced hydrophilicity. The MOF-71 and AC nanomaterials-based PEI membranes exhibited good oil/water emulsions separation due to their reliable adsorption capacity and improved fouling resistance than HNTs and SiO2 nanomaterials incorporated membranes, which could have a wide range of membrane-based water treatment applications.

Rapid co-deposition of dopamine and polyethyleneimine triggered by CuSO4/H2O2 oxidation to fabricate nanofiltration membranes with high selectivity and antifouling ability

Membrane surface properties play important roles in the separation performance and fouling behavior during the membrane-based water treatment processes. Mussel-inspired polydopamine (PDA) layer with abundant functional groups can endow the membrane surface with increased hydrophilicity as well as extraordinary versatility and creative potential for further functionalization toward specific applications. However, the slow deposition rate still limits its application in membrane modification. In this study, rapid deposition of the PDA layer on the surface of the polysulfone membrane was realized by catalytic oxidation using CuSO4/H2O2. Meanwhile, polyethyleneimine (PEI) was introduced to co-deposit with PDA to obtain a hydrophilic, uniform, and electroneutral separation layer for the nanofiltration membrane. An optimized stoichiometry of modifiers and oxidants was obtained by UV–vis absorbance measurement. The membrane surface properties including surface morphology, roughness, chemical element compositions, wettability, and charge behavior before and after modification were characterized through various techniques. The optimized PDA/PEI modified membrane (a-Cu(15)-PDA/PEI) possessed higher MgCl2/NaCl and dye/salt selectivities as well as improved anti-fouling performance compared to the commercial NF-270 membrane. Furthermore, the Gaussian simulation combined with XPS analysis illustrated that the introduction of Cu2+/H2O2 accelerated the dopamine oxidation and facilitated the formation of CO quinoid structures, thus providing more reactive sites for the Schiff base reaction in the PDA/PEI co-deposition process. The results from this study provide theoretical foundations for improving nanofiltration membrane performances by PDA/PEI modification.

Highly-efficient cathodic lysis of biofilm on conductive carbon nanotube membranes

Biofouling is a major problem observed with membrane-based water treatment systems. In this work, cathodic lysis of bacteria and biofilms on carbon nanotube (CNT) membrane was investigated as a novel mechanism for biofouling reduction. Considering the biofilm growth cycle, electrolysis of sessile bacteria and established bacterial biofilms were separately investigated. The results showed that cathodic electrolysis at 3.0 V for 3 h effectively eliminated 99.23% of the sessile bacteria on the CNT membrane. An extended treatment of mature biofilm for 21 h led to 93.92% reduction in viable bacterial density and 98.6% decrease in biofilm coverage. Besides, analyses of the membrane permeate revealed that the biofilm lysis released cell contents into the CNT matrix, which were subsequently removed by electrolysis. As a result, the normalized transmembrane pressure for the fouled membrane decreased from 4.23 to 2.06 after 21 h of electrolysis. Moreover, the cathodic lysis of bacteria and biofilm by the low-voltage electric field was mainly ascribed to the electro-generated H2O2 and the associated bio-electrochemical effects. This work provided a facile approach for in-situ mitigation of biofouling caused by chlorine-resistant bacteria, which was conducive to energy-efficient operation of membrane-based water treatment facilities.