Fouling Control Research Articles

Gravity-Driven Membrane Filtration with Passive Hydraulic Fouling Control for Drinking Water Treatment: Demonstration of Long-Term Performance at Full Scale

Gravity-Driven Membrane Filtration with Passive Hydraulic Fouling Control for Drinking Water Treatment: Demonstration of Long-Term Performance at Full Scale

Separation and purification of bromelain from pineapple residue using ultrafiltration membranes: a review

Pineapple is the most popular fruit globally, whose production increased in the last years, raising concerns about the reuse of the waste. Bromelain constitutes an attractive byproduct for various industrial sectors. Ultrafiltration (UF), widely applied in macromolecule retention processes, faces significant challenges such as fouling, which limits its effectiveness. This article reviews strategies to improve permeate flow and control fouling during bromelain recovery from pineapple residues. Prominent strategies for improving UF performance include gas sparging, vibratory or rotational modules, and pre-treatment processes like diafiltration or enzymatic treatment. While gas sparging enhances turbulence and flow, its energy efficiency is limited. Integrated approaches, such as combining MF and UF or utilizing two-stage UF systems, achieve high bromelain recovery (over 94%) and effective fouling control. Strategies involving turbulence promoters enhanced permeate flux by over 40%, while fouling mitigation techniques reduced fouling rates by up to 80%, preserving enzyme activity. These findings suggest that advancements in module design, pre-treatment processes, and turbulence-inducing systems can significantly enhance UF performance, offering promising directions for industrial bromelain recovery.

Direct membrane filtration of municipal wastewater: Assessment of different fouling control strategies to enhance its energy, environmental and economic viability

Direct membrane filtration of municipal wastewater: Assessment of different fouling control strategies to enhance its energy, environmental and economic viability

Upgrading the eastern wastewater treatment plant effluent quality in Egypt for reuse by means of in-line coagulation followed by ultrafiltration

ABSTRACT Providing clean water to Egyptian citizens is one target of the 2030 sustainable development goals. Ultrafiltration (UF) has been investigated as an advanced treatment of the largest treatment plant in Alexandria. Although UF membranes have been widely used to treat secondary effluent, fouling remains a major challenge. The effects of green and conventional coagulants on controlling ultrafiltration fouling were examined. Two different dosages of each coagulant and a combination of ferric chloride and sodium ferrate were studied in a bench-scale setup that was built and operated under identical circumstances. The results showed that the combined ferrate and ferric chloride pretreatment had the highest performance in terms of the removal of organics and turbidity as well as the reduction of membrane fouling. Fouling can be managed in terms of the normalized flux drop with only 0.5 mg/L of ferrate, which performs similarly to 2.5 mg/L of ferric chloride. The higher the dosage of alum used, the lesser the fouling control observed. The green coagulant, when used as an in-line coagulant aid/oxidant with ferric chloride at very low doses, has a favorable potential to reduce membrane fouling and improve permeated wastewater quality, making it suitable for Grade A for reuse purposes.

A critical Review on Advanced Membrane Bioreactors for Wastewater Treatment: Fouling Reduction and Energy Demand

Objectives:Rapid industrialization has highlighted the importance of addressing environmental issues and the increasing demand for water supply. As a result, innovative solutions to improve water circulation management in both public and industrial sectors have been proposed, one of which is the introduction of Membrane Bioreactor (MBR) technology. This study aims to understand the mechanisms and characteristics of membrane fouling in MBR processes and compare the associated energy consumption, with the goal of improving process efficiency and energy performance.Methods:In this study, various factors influencing the MBR process were considered to analyze the mechanisms and characteristics of membrane fouling. The impact of fouling on the process was assessed, and energy consumption was compared. Specifically, the power consumption of flat-sheet and hollow-fiber MBRs was analyzed, focusing on the proportion of energy used for microbial treatment and membrane cleaning. The Specific Energy Demand (SED) was calculated to evaluate the energy consumption efficiency of different fouling control methods in MBRs.Results and Discussion:In typical MBR processes, 68.0% (flat-sheet) and 53.0% (hollow-fiber) of the power consumption is attributed to air scouring for microbial treatment and membrane cleaning. Notably, 57.0% (flat-sheet) and 36.0% (hollow-fiber) of the power is consumed to supply air for detaching adhered foulants to maintain filtration performance. These results indicate that aeration is a major energy consumer in MBR processes. SED is a critical indicator for assessing the energy consumption of specific fouling control methods, with typical MBR processes having an SED of 0.2-0.3kWh/m3. In contrast, using a non-aerated membrane module with reciprocating inertial force for fouling control reduces SED to 0.005-0.01 kWh/m3, representing a 20-60 fold decrease in energy consumption, highlighting the need for energy reduction.Conclusion:This study provides insights into fouling reduction characteristics in MBR processes, suggesting a new paradigm for enhancing the economic feasibility of MBR technology. Applying non-aerated membrane modules to reduce energy consumption can significantly improve MBR efficiency, contributing to energy reduction and environmentally friendly technology development. Therefore, strategies to maximize energy efficiency and minimize environmental impact in MBR processes are essential.

An efficient approach in water desalination using high flux induced magnetic-field hydroxyl-functionalized MgFe2O4 /CA RO membranes with organic/inorganic fouling control capability

Reverse osmosis (RO) membranes are crucial for water purification and desalination, facing challenges like balancing permeate flux and rejection, dealing with membrane fouling, and chlorine resistance. This study focuses on developing new membranes using cellulose acetate (CA) polymers and magnetic nanoparticles of magnesium ferrite (MgFe2O4) and hydroxyl-functionalized magnesium ferrite (OH–MgFe2O4) through a phase inversion method, with and without the presence of a magnetic field, to address the limitations of RO membranes. This study conducted a unique experiment where magnetic nanoparticles migrated to the membrane surface and underwent phase exchange in the coagulation bath under the influence of a 2.0 T magnetic field. As a result, the magnetic nanoparticles were arranged in a specific pattern and evenly spread across the membrane surface, enhancing the membrane's surface characteristics and hydrophilic properties. Furthermore, the flux of the synthesized membranes experienced an increase when exposed to the magnetic field, while maintaining a consistently high rejection rate. An evaluation was conducted on the membranes' resistance to organic fouling from bovine serum albumin (BSA), inorganic fouling from scaling, and the combined effects of BSA and scaling. Based on the findings, the membranes showed a notable enhancement in their anti-fouling properties, particularly when exposed to a magnetic field. An assessment was conducted on the resistance to chlorine for both the standard and improved membranes. Comparing the flux and rejection of the membranes before and after chlorine exposure revealed a minor variation, suggesting the membrane's ability to resist surface damage from chlorine. Hence, through the creation of innovative MgFe2O4/CA and OH–MgFe2O4/CA membranes, the identified constraints of RO membranes were effectively addressed. One of the synthesized RO membranes, OH–MgFe2O4/CA, demonstrated superior performance in permeate flux, rejection, anti-fouling, and chlorine resistance when compared to MgFe2O4/CA membranes. Furthermore, the stability of the synthesized membranes was assessed through tensile strength testing, which confirmed the preservation of the membrane structure.

Effects of pre-chlorination on ultrafiltration process in directly treating seasonal high-turbidity surface water: Membrane fouling control and shock load resisting

The seasonal high turbidity in the surface water is posing great challenges to the feasibility of direct ultrafiltration (UF) due to the severe membrane fouling. In this study, a direct UF process was employed to treat the high-turbidity surface water. With the conventional operational protocols, severe membrane fouling encountered. Model fitting indicated that membrane fouling, resulting from the UF of high turbidity water, was predominantly associated with the complete obstruction of pores on the surface of the membrane and the subsequent formation of a cake layer. A pre-disinfection process using sodium hypochlorite was developed in this study, and the membrane fouling was significantly mitigated during long-term (885 h) filtration. The optimized chlorine dosage was 1.5 mg/L in treating the 800 NTU surface water, and enabled the transmembrane pressure (TMP) stabilization of UF process at a low level (<10 kpa). Pre-disinfection can effectively inactivate microorganisms and diminish the presence of microbial extracellular polymeric substances (EPS). This results in a transition from complex and viscous fouling to inorganic fouling on the cake layer caused by high turbidity water. With pre-chlorination, the adhesion force of the cake layer attached on the membrane reduced significantly to make the fouling more easily detach and be removed from on the membrane surface by the shear stress caused by the hydraulic backwash. These findings are expected to develop new insights into the membrane fouling control of UF in directly treating the seasonal high-turbidity surface water.

1-(3-Aminopropyl) imidazole (APIm) modified ultrafiltration (UF) membrane for mitigating alginate fouling caused by calcium

UF is widely used as a wastewater treatment and recycling technology. However, membrane fouling is still an important factor affecting the wide application. In this study, APIm with positive amino group was adsorbed to the surface of the carboxylated polyacrylonitrile (PAN) membrane by electrostatic force to reduce the fouling of sodium alginate (SA) caused by Ca2+. The results show that 1 v/v% APIm was selected as the optimal dosage, accompanied by the highest water flux of 330.5 L·m-2h−1 bar−1 and bovine serum albumin (BSA) rejection rate of 91.0 %. When the concentration of Ca2+ was increased to 10 mM, the Ca2+ catch amount increased to 48.25 mg/cm2. The main anti-fouling mechanism was that APIm captured a certain amount of Ca2+ in situ, destroyed the complex structure of sodium alginate (SA) and Ca2+. Then the fouling layer was easy to be removed by physical cleaning. At the concentration of 10 mM Ca2+, the membrane flux recovery rate of 1 v/v% APIm membrane was increased to 80.1 %. This study demonstrates a fouling control strategy for in-situ removal of Ca2+ bound SA fouling, providing a new approach for the future development of UF membrane.

Spatial variability of cake layer in membrane fouling of full-scale MBR: New insights and implications

The spatial variability of the cake layer formed on the hollow fiber membranes during the operation of a full-scale membrane bioreactor (MBR) has been thoroughly investigated, samples from the bulk phase of the reactor and cakes formed on the membrane surface with different locations (i.e., inner layer of the cake (Cake-I), central layer of the cake (Cake-C), and outer layer of the cake (Cake-O)) were collected. The results showed that the viscous nature of proteins, the main component of extracellular polymeric substances (EPS),as well as the hydrophobicity of the protein secondary structure, were factors that led to variations in particle size (Cake-I = 566 μm > Cake-C = 283 μm > Cake-O = 92.2 μm > Bulk sludge = 59.7 μm) and total interaction energy (Cake-I = −216.39 × 104 KT > Cake-C = −68.35 × 104 KT > Cake-O = −30.42 × 104 KT > Bulk sludge = −30.08 × 104 KT) between the spatially varying cake layers. Numerous filamentous bacteria were found in the MBR, and genes related to membrane plugging processes (such as polysaccharide synthesis, surface attachment, and amino acid degradation) of the microbial community composition were regulated within the cake layers. These new insights could be beneficial to developing fouling control and membrane cleaning strategies.

Critical flux-based fouling control method for forward osmosis during simultaneous thickening and digestion of waste activated sludge

The use of forward osmosis (FO) membranes for simultaneous thickening and digestion of waste activated sludge (WAS) (FO-MSTD) has recently garnered significant interest. However, a major challenge hindering the widespread adoption of the FO-MSTD process is severe membrane fouling, which results from increasing sludge concentrations and deteriorating sludge properties. In response, this study proposes a novel FO membrane fouling control strategy based on the critical flux concept, involving a variable draw solution (DS) operating mode. Two operating modes were examined based on the critical flux behavior of the FO membrane: a constant DS concentration mode (with a fixed DS concentration of 1.5 M, referred to as Constant DS1.5) and a variable DS concentration mode (with varying DS concentrations at different operational stages, referred to as Variable DS1.5-1.0 and Variable DS1.5-0.75). Over 21 days of operation, the MLSS concentrations of WAS in the Constant DS1.5, Variable DS1.5-1.0, and Variable DS1.5-0.75 reactors increased from initial values of 3.46, 3.88, and 4.20 g/L to 35.2, 31.5, and 29.2 g/L, respectively. Concurrently, the cumulative digestion rates of MLVSS in the three FO-MSTD processes reached 29.3 %, 29.0 %, and 36.3 %, respectively. After adjusting the DS concentration, the FO membrane flux decay rates for Constant DS1.5, Variable DS1.5-1.0, and Variable DS1.5-0.75 were 57.7 %, 49.4 %, and 13.8 %, respectively. In addition to experiencing a lower flux decline, the Variable DS1.5–0.75 mode achieved a significantly higher flux recovery rate of 98.5 % compared to the other two modes. Moreover, the biovolume of proteins and microorganisms in the membrane fouling layer decreased by 85.2 % and 72.7 %, respectively, in the Variable DS1.5–0.75 mode compared to the Constant DS1.5 mode. These findings indicate that operating with a DS below the critical concentration can significantly improve the reversibility of membrane fouling and reduce the presence of organic and biological foulants in the fouling layer, thereby mitigating membrane fouling in the FO-MSTD reactor.

Surface with wettability gradient — A novel approach for crystallization fouling control on the horizontal falling film flow

To manage scaling on heat transfer surfaces, using chemical-based antifouling treatments takes a toll on the environment, and related maintenance costs are significant. A unique and environmentally friendly scale mitigation strategy is developed in this work. By manipulating the scale layer distribution using surface wettability gradients, stronger flow shear and weaker scaling adhesion are achieved, facilitating self-cleaning process. Experimental work utilizes a horizontal-tube falling-film evaporator to mimic multiple-effect distillation process. A millimetric wettability pattern – alternating hydrophilic and hydrophobic regions – is created by coating stainless steel tubes. The results show scale layers (calcium carbonate) were either thicker in hydrophilic regions and thinner in hydrophobic regions or had approximately uniform thickness in both regions but cracks in scale layers near wettability boundaries. Scale layers wash-off with flow is observed on patterned tubes, demonstrating self-cleaning process. In contrast to persistent deterioration in overall HTC (heat transfer coefficient) for baseline tube (77 % of initial HTC after 192 h), HTC on patterned tubes initially increases due to surface wetting effects, then maintains roughly constant (15 % higher than that of baseline after 192 h) along with lower scale mass. This work provides a novel scaling control method, a potential “green” alternative to current industry scale-control practices.

Unveiling the impacts of salts on halotolerant bacteria during filtration: A new perspective on membrane biofouling formation in MBR treating high-saline organic wastewater

In recent decades, membrane bioreactor (MBR) has been prevalently employed to treat high-saline organic wastewater, where the halotolerant microorganisms should be intensively utilized. However, limited works were devoted to investigating the biofouling characteristics from the perspective of the relationship between halotolerant bacteria and salts. This work filled the knowledge gap by exploring the biofouling formation mechanisms affected by high salinity. The results showed that the amount of negative charge on halotolerant bacteria surface was significantly reduced by high content of NaCl, probably leading to the obvious cell agglomeration. Despite the normal proliferation, the halotolerant bacteria still produced substantial EPS triggered by high salinity. Compared with the case of control without salt addition, the enhanced biofouling development was observed under high-saline conditions, with the fouling mechanism dramatically transformed from cake filtration to intermediate blocking. It was inferred that the halotolerant bacteria initially adhered on membrane created an extra filter layer, which contributed to the subsequent NaCl retention, resulting in the simultaneous occurrences of pore blockage and cake layer formation because of NaCl deposition both on membrane pores as well as on biofilm layer. Under high-saline environment, remarkable salt crystallization occurred on the biofilm layer, with more protein secreted by the attached halotolerant bacteria. Consequently, the potential mechanisms for the enhanced biofouling formation influenced by high salinity were proposed, which should provide new insights and enlightenments on fouling control strategies for MBR operation when treating high-saline organic wastewater.

Promoted production of Fe(IV)/Fe(V) intermediates in the calcium peroxide/ferrate(VI) process for low-damage removal of algal contaminants and membrane fouling control

Ultrafiltration (UF) is widely employed for harmful algae rejection, whereas severe membrane fouling hampers its long-term operation. Herein, calcium peroxide (CaO2) and ferrate (Fe(VI)) were innovatively coupled for low-damage removal of algal contaminants and fouling control in the UF process. As a result, the terminal J/J0 increased from 0.13 to 0.66, with Rr and Rir respectively decreased by 96.74 % and 48.47 %. The cake layer filtration was significantly postponed, and pore blocking was reduced. The ζ-potential of algal foulants was weakened from −34.4 mV to −18.7 mV, and algal cells of 86.15 % were removed with flocs of 300 µm generated. The cell integrity was better remained in comparison to the Fe(VI) treatment, and Fe(IV)/Fe(V) was verified to be the dominant reactive species. The membrane fouling alleviation mechanisms could be attributed to the reduction of the fouling loads and the changes in the interfacial free energies. A membrane fouling prediction model was built based on a long short-term memory deep learning network, which predicted that the filtration volume at J/J0= 0.2 increased from 288 to 1400 mL. The results provide a new routine for controlling algal membrane fouling from the perspective of promoting the generation of Fe(IV)/Fe(V) intermediates.

Effect of In Situ Aeration on Ultrafiltration Membrane Fouling Control in Treating Seasonal High-Turbidity Surface Water

Effect of In Situ Aeration on Ultrafiltration Membrane Fouling Control in Treating Seasonal High-Turbidity Surface Water

Effect of Mn2+ on RO membrane organic fouling: Insights into the complexation and interfacial interaction

RO process is commonly used to treat and reuse manganese-containing industrial wastewater. Nevertheless, even after undergoing multi-stage treatment, the secondary biochemical effluent still exhibits a high concentration of Mn2+ coupled with organics entering the RO system, leading to membrane fouling. In this work, we systematically analyze the RO membrane organic fouling processes and mechanisms, considering the coexistence of Mn2+ with humic acid (HA), sodium alginate (SA), bovine serum albumin (BSA) and their mixtures (HBS). The impact of Mn2+ on membrane fouling was HBS > SA > HA > BSA, controlling polysaccharide pollutant concentrations should be a priority for mitigating membrane fouling. In the presence of Mn2+ with HA, SA, or HBS, membrane fouling is primarily attributed to the complexation of organics and Mn2+ and the facilitation of interfacial interaction energy. RO membrane BSA fouling was not directly affected by Mn2+, the addition of Mn2+ induced a salting-out effect, leading to the deposition of BSA in a single molecular on the membrane. Simultaneously, adhesion energy hinders the deposition of BSA on the membrane, resulting in milder membrane fouling. This study provided the theoretical basis and suggestions for RO membrane organic fouling control in the presence of Mn2+.

Resources recovery from domestic wastewater by a combined process: anaerobic digestion and membrane photobioreactor

Anaerobic and membrane technologies are a promising combination to decrease the energy consumption associated with wastewater treatment, allowing the recovery of resources: organic matter as biomethane, nutrient assimilation by microalgae and reclaimed water. In this study, domestic wastewater was treated using a combination of an upflow anaerobic sludge blanket sludge reactor (UASB) and a membrane photobioreactor (MPBR). The outdoor facilities were operated continuously for three months under unfavourable environmental conditions such as lack of temperature control, winter season with lower solar irradiation and lower daylight hours which was a challenge for the present work, not previously described. The energetic valorisation of the organic matter present in the wastewater by biomethane produced in the UASB would contribute to reducing overall facilities’ energy requirements. The ultrafiltration (UF) membrane facilitated the harvesting of biomass, operating at 10 L·h−1·m−2 during the experimental period. Although the main contribution to fouling was irreversible, chemical cleanings were not necessary due to effective fouling control, which prevented the final TMP from exceeding 25 kPa. In addition, microalgae-bacterial consortium developed without prior inoculation were harvested from the MPBR using membrane assistance. The obtained biomass was also successfully tested as a biostimulant for corn germination/growth, as well as a biopesticide against Rhizoctonia solani and Fusarium oxysporum.Graphical abstract

Stratified structure of membrane clogs observed in full scale cross-flow tubular ultrafiltration (UF) system: Fouling characterization and a proposed two-stage formation mechanism

Membrane fouling remains a significant challenge in wastewater treatment, hindering both efficiency and lifespan. This study reports a distinct phenomenon of stratified membrane clogging observed in a full-scale cross-flow tubular ultrafiltration (UF) system treating sludge anaerobic digestion (AD) reject water. The distinct stratified structure, comprising inner and outer layers within the cake layer, has not been previously described. This research involved characterizing the filtration performance, analyzing membrane clog composition, and proposing a two-stage formation mechanism for the stratified clogs. It was revealed that higher inorganic and lower organic content in the outer layer compared to the inner layer. Acid and alkali treatments demonstrated the effectiveness of combined cleaning strategies. A mathematical model was developed to determine the critical conditions for stratified clog formation, influenced by membrane flux and cross-flow velocity (CFV). It is proposed that outer layer forms through long-term selective deposition, while the inner layer results from short-term dewatering within limited tubular space. High CFV (>2.5 m/s) prevents inner layer formation. Critical conditions for stratification occur at a flux of 18 L/m2/h with a CFV of 0.1 m/s or 65 L/m2/h with a CFV of 0.35 m/s. This study contributes a novel understanding of stratified membrane clogging, proposing a two-stage formation mechanism and identifying critical conditions, which provides insights for effective fouling control strategies and maintenance of operational efficiency for membrane systems.

Development of conductive two-dimensional metal-organic frameworks self-cleaning membrane for enhanced antibiotics rejection and sustainable fouling mitigation

In this study, a novel electroactive NF membrane was constructed for ultrafast rejection of antibiotics with high selectivity and self-cleaning by incorporating a conductive two dimensional metal-organic frameworks (Cu-HHTP) into porous polyvinylidene fluoride (PVDF) matrix with facile and scalable non-solvent induced phase inversion strategy. Cu-HHTP membrane showed two orders of magnitude higher permeability (198.4 L m−2 h−1·bar−1) than the commercial and most reported NF membranes without sacrificing rejection toward negatively charged tetracycline (95.4 %), positively charged vancomycin (99.9 %) and neutrally charged valinomycin (99.9 %). Interestingly, loading Cu-HHTP with hydrophilic and porous nature can break the permeability-rejection trade-off effect and the mechanism was due to the improved water channel and pollutants sieving. Furthermore, it has stable antibiotics rejection and high flux recovery rate of 93.9 % for long-term filtration of wastewater over 264 h with low energy consumption of 0.1007 W h/L and without adding chemical cleaning agents, which demonstrated its excellent fouling control and stability. This study may guide the development of advanced self-cleaning NF membranes tailored for removal of small molecular emerging contaminants.

Sustainable control of organic-inorganic combined fouling of electroactive ultrafiltration membrane during electrocatalytic-driven self-cleaning process: Mechanism and implications

Organic-inorganic combined fouling of membrane is a tough problem that restrained its application in water treatment, which was insufficient and non-sustainable to be alleviated by conventional chemical cleaning. Herein, a facile and sustainable control strategy was developed to mitigate biopolymer-Ca2+ combined fouling for an electroactive metal-organic framework ultrafiltration membrane. Bovine serum albumin (BSA) and sodium alginate (SA) were selected as model biopolymer. The results showed BSA and SA fouling both accelerated with increasing Ca2+ concentration (0–1.0 mM) via calcium bridging action and hydraulic cleaning was insufficient to restore flux (flux recovery < 7 %). By comparison, flux can be fully recovered by applying electricity to all combined fouling, suggesting membrane presented outstanding self-cleaning performance. According to the free radical quenching test and physicochemical property of biopolymer, fouling control mechanism was revealed because in-situ electro-generated OH and O2− free radicals caused decomplexation of biopolymer and Ca2+, and then degraded biopolymer into smaller and less hydrophobic fragments that repulsed membrane. Extended Derjaguin–Landau–Verwey–Overbeek theory further unveiled the foulants-membrane interaction shifted from attraction to repulsion after self-cleaning. This strategy has the advantages of low chemical cleaning reagents and energy consumption, which may provide the guidance for sustainable control of organic-inorganic combined membrane fouling.

Application of the multi-wavelength UV-LED/chlorine process to improve reverse osmosis membrane performance for reused water treatment in the steel industry

ABSTRACT Membrane fouling is a prominent issue that affects the stable and efficient operation of reverse osmosis (RO) in reused water treatment. In this study, a zero-discharge RO system was adopted to treat the ultrafiltration permeate from a steel plant with the combined multi-wavelength UV-LED/chlorine process, focusing on organic structure modification and membrane fouling control. The results showed that the UV-LED/chlorine process could not only efficiently remove the dissolved organic carbon and the total nitrogen of the RO influent but also alter the organic substances from large molecules to small ones. In addition, the longer wavelength of a 295 nm UV-LED/chlorine process exhibited a greater RO permeate flux of 158 LMH, as compared to the shorter wavelength of 255 nm with the flux of 152 LMH. Moreover, compared to the single-wavelength, the dual-wavelength UV-LED/chlorine process played a more significant role in RO filtration performance, which induced a looser and thinner foulant structure, resulting in an 8% larger permeate flux and recovery at 275 + 295 nm than at 295 nm. This study demonstrated that the combined UV-LED/chlorine process could effectively alleviate RO membrane fouling. Our findings can provide theoretical and technical support for the sustainable development of membrane-based reused water treatment in the steel industry.