Spiral-wound Membrane Research Articles

Analysis and prediction of SWM feed spacer performance based on CFD results with an emphasis on the effect of micro-scale lateral and longitudinal washing flows

In reverse osmosis applications, feed spacers are used in spiral wound membranes to separate the membrane surfaces and enhance mass transfer while incurring an acceptable pressure drop. In this study, an attempt has been made to understand the effect of spacer characteristics, such as arrangement and size, on mass transfer and pressure drop. Power-law equations were successfully developed to describe different spacer performance measures as a function of Reynolds number (Re), where both the multiplier of the Re term and the Re exponent vary for each spacer arrangement. Although at the macro level, it was not possible to adequately correlate the equation parameters with the spacers’ geometrical parameters (such as porosity), examining the post-processed CFD results at the micro level led to explanations for the observed concentration profiles, trends in spacer performance and changes in the equation parameters. A key observation was the importance of lateral flow recirculation, which was termed side-washing. Overall, based on the Spacer Configuration Efficacy performance measure and by assessing the trade-off between Sherwood number and pressure drop, the Woven configuration shows the best performance among the spacer arrangements and range of flowrates studied.

Simulation of spiral-wound pressure retarded osmosis for harvesting osmotic power: Module-level modeling and implications of feed pre-treatment

A process-scale model for pressure retarded osmosis (PRO) using a 1-dimensional representation of the spiral-wound membrane is presented. Comparing a length-averaged modeling approach with a true counter-current approach reveals that the former holds only for relatively short membrane lengths while it over-predicts the net power output for longer membranes. For a membrane line with eight spiral-wound elements in series, the length-average model over-predicted the PRO performance by 20 %. The model was further used to assess the impact of feed pre-treatment on process performance and optimal process design. Feed pre-treatment was found to be a dominant factor affecting the optimal inlet feed flow rate and the power output. Our model suggests that for a moderate to high feed pre-treatment requirement the inlet feed flow rate is close to minimum feed flow rate of the membrane module. In the absence of feed pre-treatment a power density of 143 and 284 W m−2 for CTA and TFC membranes, respectively, was found. When feed pre-treatment with 100 Wh m−3 was employed these numbers dropped to 48 and 94 W m−2.

A comprehensive evaluation of the temporal and spatial fouling characteristics of RO membranes in a full-scale seawater desalination plant

The fouling of seawater reverse osmosis (SWRO) membranes remains a persistent challenge in desalination. Previous research has focused mainly on fouling separately; however, organic, inorganic, and biofouling can coexist and influence each other. Hence, in-depth study of the spatiotemporal changes in actual combined fouling in full-scale seawater desalination will provide more effective information for fouling investigation and control. In this study, we monitored (i) the operational performance of a full-scale desalination plant for 7 years and (ii) the development and characterization of membrane and spacer fouling at different locations of spiral-wound membrane modules sampled after 2.5-, 3.5-, and 7-year operation. The findings showed that (i) operational performance indicators declined with time (normalized flux 40 % reduction, salt rejection 2 % in 7 years), with a limited effect of the 20-day cleaning frequency, (ii) fouling accumulation in the membrane module mainly occurred at the feed side of the lead module and the microbial community in these area exhibited the highest diversity, (iii) the dominant microbial OTUs belonged mainly to Proteobacteria (43–70 %), followed by Bacteroidetes (10–11 %), (iv) Phylogenetic molecular ecological networks and Spearman correlation analysis revealed that Chloroflexi (Anaerolineae) and Planctomycetes were keystone species in maintaining the community structure and biofilm maturation and significantly impacted the foulant content on the SWRO membrane, even with low abundance, and that (v) fouling accumulation was composed of polysaccharides, soluble microbial products, marine humic acid-like substances, and inorganic Ca/Fe/Mg/Si dominate the fouling layer of both the membrane and spacer. Overall, variation partitioning analysis quantitatively describes the increasing contribution of biofouling over time. Ultimately, the organic‒inorganic-biofouling interaction (70 %) significantly contributed to the overall fouling of the membrane after 7 years of operation. These results can be used to develop more targeted fouling control strategies to optimize SWRO desalination plant design and operation.

Highly efficient and sustainable cationic polyvinyl chloride nanofibrous membranes for removal of E. coli and Cr (VI): Filtration and adsorption

Both plastic (e.g., polyvinyl chloride (PVC)) solid waste and bacteria/heavy metal ions-containing wastewater pose a severe threat to the environment, which must be addressed simultaneously by developing highly efficient and sustainable strategies. Novel cationic PVC nanofibrous membranes with high filtration and adsorption capability were fabricated by electrospinning and surface grafting, and then employed for the removal of bacteria (e.g., E. coli) and hexavalent chromium (Cr (VI)) ions for wastewater treatment. A cationic pendant, methylimidazolium, was covalently anchored on the surface of PVC nanofibers and verified using FTIR-ATR, NMR, and SEM measurements. As a result, the optimized cationic PVC nanofibrous membrane (PVC-MIM) exhibited remarkable filtration efficiency for E. coli (LRV ≥ 6.1) from contaminated water, and a maximum adsorption capacity of 285.7 mg/g against Cr (VI). Kinetics, isotherms, and thermodynamics of the nanofibrous PVC-MIM membrane in the adsorption process were extensively investigated. The separation mechanism was proposed based on size exclusion, charged interactions, and hydrogen bonding/coordination between the membrane and the targets. Used sewer pipes and electric cables were employed as raw materials to fabricate modified nanofibrous membranes (0.9 g) to then manufacture of a spiral-wound PVC-MIM nanofibrous membrane cartridge. The resulting system exhibited a retention rate as high as 100 % when 24 L of simulated tanning wastewater containing concentrated suspended solids, oil, ammonia–nitrogen, chloride, and other pollutants were tested for a dynamic adsorption process. Furthermore, the nanofibrous membrane cartridge could be recycled ten times while the regeneration ratio remained as high as 91.0 %.

Step-Nucleation In Situ Self-Repair to Prepare Rollable Large-Area Ultrathin MOF Membranes.

Ultrathin membranes with ultrahigh permeance and good gas selectivity have the potential to greatly decrease separation process costs, but it requires the practical preparation of large area membranes for implementation. Metal-organic frameworks (MOFs) are very attractive for membrane gas separation applications. However, to date, the largest MOF membrane area reported in the literature is only about 100 cm2 . In the present study, a new step-nucleation in situ self-repair strategy is proposed that enables the preparation of large-area (2400 cm2 ) ultrathin and rollable MOF membranes deposited on an inexpensive flexible polymer membrane support layer for the first time, combining a polyvinyl alcohol (PVA)-metal-ion layer and a pure metal-ion layer. The main role of the pure metal-ion layer is to act as the main nucleation sites for MOF membrane growth, while the PVA-metal-ion layer acts as a slow-release metal-ion source, which supplements MOF crystal nucleation to repair any defects occurring. Membrane modules are necessary components for membrane applications, and spiral-wound modules are among the most common module formats that are widely applied in gas separation. A 4800 cm2 spiral-wound membrane modulewas successfully prepared, demonstrating the practical implementation of large-area MOF membranes.

Investigation of micro lattice spiral wound membrane structures availing DLP and FDM techniques for water treatment

This study addressed the challenge of reducing water contaminants using Spiral Wound Membrane (SWM) units in desalination and water treatment. Through additive manufacturing, we developed complex micro-lattice feed-spacer structures using FlexBLK 20, Pro-BLK10, ToughBLK 20, PLA, PETG, and ABS materials. The AHPTOPSIS statistical method indicated an ideal solution with Digital Light Processing (DLP) conditions showing a 20 μm layer thickness, FlexBLK-20 material, diamond structure, and for Fused Deposition Modeling (FDM) conditions, a 0.1 mm layer thickness, PLA material, and gyroid structure. Significant findings include a decrease in surface roughness by 79.67%–85.25% for DLP, an elongation increase of 50%–91.67%, and tensile strength improvement between 0.07%–40.83%. DLP printed feed spacers showcased better surface distributions than FDM, attributed to finer layers and higher density printing. Additionally, DLP printing resulted in a 32.02% increase in residual stress, suggesting superior compressive resistance. In thermal analyses, both DLP and FDM materials showed thermal stability up to 380 °C–450 °C. This research indicates that DLP printed feed spacers, with their enhanced properties, are potentially more efficient for water purification systems, providing smoother surface, better filtration, and increased durability.

Increasing Performance of Spiral-Wound Modules (SWMs) by Improving Stability against Axial Pressure Drop and Utilising Pulsed Flow.

Spacer-induced flow shadows and limited mechanical stability due to module construction and geometry are the main obstacles to improving the filtration performance and cleanability of microfiltration spiral-wound membranes (SWMs), applied to milk protein fractionation in this study. The goal of this study was first to improve filtration performance and cleanability by utilising pulsed flow in a modified pilot-scale filtration plant. The second goal was to enhance membrane stability against module deformation by flow-induced friction in the axial direction ("membrane telescoping"). This was accomplished by stabilising membrane layers, including spacers, at the membrane inlet by glue connections. Pulsed flow characteristics similar to those reported in previous lab-scale studies could be achieved by establishing an on/off bypass around the membrane module, thus enabling a high-frequency flow variation. Pulsed flow significantly increased filtration performance (target protein mass flow into the permeate increased by 26%) and cleaning success (protein removal increased by 28%). Furthermore, adding feed-side glue connections increased the mechanical membrane stability in terms of allowed volume throughput by ≥100% compared to unmodified modules, thus allowing operation with higher axial pressure drops, flow velocities and pulsation amplitudes.

A model for the observed secondary-maximum in backwash-effluent-TDS-data obtained during backwash of spiral-wound RO membranes

Observation of a “secondary maximum” in the effluent Total Dissolved Solids (TDS) concentration data, during back-washing of micro-scale spiral-wound Reverse Osmosis (RO) membranes, has been reported (Varma and Chatterjee, 2023). This observation is of interest because a “wash-out” process for any system, may be expected to produce effluent water, which shows an exponential decline in the contaminant, from its initial peak concentration, to that of the water used for washing. Hence the observation of a “secondary maximum” in the back-wash effluent TDS data is interesting and has been examined experimentally in (Varma and Chatterjee, 2023). In this work, we present a mathematical model, which can explain the above observations. This model shows that high TDS water is trapped in the RO membrane element, when the RO system is shut-off. A complete wash-out of this high TDS water, which is held close to the membrane surface requires RO permeate osmotic backwash of a “critical” volume. This “critical” RO permeate volume, can be estimated from the method used in this study. The model is based on coupled-unsteady-state material balances for the salt held in different pseudo-compartments within the RO membrane module.

Rejection of perfluoroalkyl acids by nanofiltration and reverse osmosis in a high-recovery closed-circuit membrane filtration system

Poly- and perfluoroalkyl substances (PFASs), especially perfluoroalkyl acids (PFAAs), have garnered broad attention due to their near ubiquitous presence in environmental and biological matrices, recalcitrant nature, and reported negative human health impacts. Processes using high-pressure membranes such as reverse osmosis (RO) and nanofiltration (NF) have been investigated as PFAA treatment technologies due to their ability to separate dissolved solutes such as inorganic ions, and small molecular weight organic compounds. The major drawback associated with high-pressure membranes is management of the concentrate stream produced during treatment. As a result, high recovery membrane system configurations have been developed with the goal of minimizing volume of concentrate requiring disposal. In the context of PFAS treatment, high-recovery membrane applications may be beneficial; PFAS residuals could be concentrated allowing advantages in terms of disposal, e.g., more effective application of PFAS destruction technologies. The objective of this study was to evaluate the PFAA rejection performance of commercially available high-pressure membranes in a pilot-scale closed-circuit membrane filtration (CCMF) system. The rejection of nine PFAAs by four spiral wound membrane products spanning characteristics ranging from loose NF to seawater RO was investigated during and through two closed-circuit sequences each operating up to 97% recovery. Mechanisms of PFAA rejection including steric and electrostatic exclusion were investigated through analysis of generated data, and ionic strength experiments. Additionally, short-term foulant accumulation during CCMF and normalized energy analysis were performed by monitoring the calculated temperature corrected specific flux (TCSF) and design software simulations, respectively. Results from this study demonstrate that tight NF and RO membranes are effective for separating and concentrating PFAAs during high recovery CCMF operation. During CCMF sequences to 97% water recovery, the NF90, CR100, and SW30 membranes evaluated exhibited overall rejection values of > 98.3% for the PFAAs quantified in this study. The loose NF membrane element investigated (NF270) exhibited the lowest PFAA rejection performance during the high recovery experiments, particularly at water recoveries > 90%. Diminished PFAA rejection performance of the NF270 is likely a result of both steric and electrostatic exclusion being significant separation mechanisms. Feed water amended with sodium sulfate yielded lower rejection for PFAAs by the NF270 compared to unamended feed water supporting the hypothesis that that high recovery CCMF operation may negatively impact PFAS rejection by loose NF membranes, particularly membranes that rely on electrostatic exclusion for separation of anions.

Unveiling the potential of composite water-swollen spiral wound membrane for design of low-cost raw biogas purification

The present study aims to verify a novel purification method for raw biogas using water-swollen composite membranes. In two module configurations, we generated water-swollen polymer gel layers on thin-film composite membranes to separate methane from other biogas species. The primary driving force of the biogas separation is the solubility differences between major biogas species. The carbon dioxide solubility, many times higher than methane, effectively rejected methane from the water-swollen membranes and resulted in the retentate concentration of 97 vol% methane for raw biogas and 98 vol% for synthetic gas. Two membrane modules connected in parallel increased the methane recovery ratio up to 58 %. At a pressure of 3 bar the water-swollen membrane proved efficient in desulfurizing feed biogas producing an outlet stream containing a low concentration of H2S of an order of 10 ppmv.

Impact of SWMM Fouling and Position on the Performance of SWRO Systems in Operating Conditions of Minimum SEC.

Due to water stress in the world in general desalination technologies are becoming increasingly important. Among the available technologies, reverse osmosis (RO) is the most widespread due to its reliability and efficiency compared to other technologies. The main weakness of RO is the loss of performance due to membrane fouling, which usually affects the water permeability coefficient (A), causing it to decrease. In RO desalination plants, fouling does not affect all spiral wound membrane modules (SWMMs) in the pressure vessels (PVs) in the same way. This will depend on the type of fouling and the position of the SWMM inside the PV. In this study, the impact of A and the position of the SWMM on the performance of the RO system is analyzed. For this purpose, decrements of up to 50% have been assumed for the seven SWMMs in series considering nine commercial SWMM models. The operating point analyzed is that which minimizes the specific energy consumption (SEC), a point obtained in a previous work carried out by the authors. The results show how the impact of A on the SWMM in the first position is more significant than the impact on modules that are in another position for the nine SWRO models studied. A drop of 50% in the coefficient A of the first element produces a permeate loss in the pressure pipe between 0.67 and 1.35 m3 d-1. Furthermore, it was observed that the models with the lowest coefficient A exhibited the highest performance losses in terms of permeate production when A was decreased.

Performance evaluation of pilot-scale reverse osmosis spiral wound membrane for water desalination systems

Abstract The increasing scarcity of potable water increases the demand for non-conventional potable water resources such as desalination. Experiments are carried out using a pilot-scale device of the desalination process for three configurations of membrane allocation inside the pressure vessel. Configuration (A) is one pressure vessel containing one spiral wound membrane (SWM), (B) is four pressure vessels each containing one SWM connected in parallel, and (C) is one pressure vessel containing four membranes connected in parallel. The effect of applied pressure, temperature, and water salinity is studied. Moreover, a mathematical model using ANSYS Fluent was developed and verified using the experimental data. The mathematical model is applied to an idealized case of an actual desalination plant. The main findings are (1) configurations (B) and (C) accomplished higher permeate discharge comparing to (A) by an average percentage of 60 and 50, respectively, while (C) has the lowest output salinity by 30% from configuration (A). (2) The mathematical model is found to reduce the operating pressure of the plant by 8%.

Role of permeability coefficients in salinity gradient energy generation by PRO systems with spiral wound membrane modules

Processes that can transform a salinity gradient into electrical energy have gained attention in recent years. One such process, which uses semipermeable membranes to generate electrical energy through a turbine, is pressure retarded osmosis (PRO). As a potential renewable energy technology, this process could also be integrated in desalination plants to reduce the energy consumption. However, principally because of certain drawbacks concerning membrane and module characteristics, PRO technology has not yet been fully exploited at commercial scale. This study aims to assess the impact of membrane permeability coefficients on the energy generated by full-scale single-stage PRO systems. This allow an evaluation of the performance of PRO modules in series considering variation of the permeability coefficients that may be due to the impact of fouling. An evaluation was made of the HTI OsMem™ 2521 spiral wound membrane module considering a diameter of 8 inches (high up-scaled active area) and different permeability coefficient ranges. The results showed that a 50% water permeability coefficient decrease would produce an approximately 25% decrease in the amount of energy that could be generated, while a 50% increase in the solute permeability coefficient would have virtually no effect when considering optimal operating points. Variation of the water permeability coefficient had more impact on the potential amount of generated energy than variation of the solute permeability coefficient.

Performance Evaluation of UF Membranes Derived from Recycled RO Membrane, a Step towards Circular Economy in Desalination.

Reverse osmosis (RO) spiral wound membrane generation reached 93.5% in 2020, resulting in 14,000 tons of used RO membranes being discarded annually into landfills, which is unprecedented. The current study aims to chemically convert the end-of-life RO membrane, followed by its performance evaluation and microbial removal efficiency on three different sources of water, i.e., tap water (TW), integrated constructed wetland permeate (ICW-P), and membrane bio-rector permeate (MBR-P), respectively. This was accomplished by selecting 6 years of spent Filmtech (LC-LE-4040) thin film composite type brackish water reverse osmosis (BWRO) membrane, followed by alkaline and acidic cleaning for 2 h. Finally, the conversion was carried out by 6% sodium hypochlorite (NaOCl) with 300,000 ppm/h exposure by active system (AS) using the clean in place CIP pump at 2 bars for 10 h duration. The membrane demonstrated 67% water recovery and 1% saltwater rejection, which means RO membrane now converted into recycled RO (R-RO) or (UF) by removal of the polyamide (PA) layer. Water recovery was 67% for TW, 68% for ICW-P, and 74% for MBR-P, respectively, with the consistent saltwater rejection rate of 1% being observed, while R-RO exhibited an effective COD removal of 65.79%, 62.96%, and 67.72% in TW, ICW-P, and MBR-P, respectively. The highest turbidity removal of 96% in the ICW-P was also recorded for R-RO. For morphological properties, SEM analysis of the R-RO membrane revealed a likewise appearance as a UF membrane, while pore size is also comparable with the UF membrane. The most probable number (MPN) also showed complete removal of total coliforms after passing through the R-RO membrane. These features made the R-RO membrane an excellent choice for drinking water treatment and wastewater treatment polishing steps. This solution can help developing nations to be efficient in resource recovery and contribute to the circular economy.

Understanding of surface fouling of brackish water reverse osmosis spiral wound membrane using an integrated analysis of seawater quality and membrane autopsy

To understand the cause of the scale, an integrated analysis of the saline water quality and discarded reverse osmosis membranes was developed. Damaged areas on the membrane were excised and characterized by the Fujiwara test, infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. A spatula and sonication were used to remove scale. Thermodynamic modeling (PHREEQC) was used to predict scale formation at 75 bar, resulting in saturation index values for both mixed and pure compounds. Fujiwara's test revealed damage to the polyamide and organic fouling by polysaccharides, silica, and aromatics. Thermo-oxidative decomposition and residual masses of metal oxides and salts were observed. The microscopy detected incrustations in the membrane by analyzing compounds with silicon, oxygen, calcium, magnesium, aluminum, etc. The modeling indicated the low-solubility compounds of scale are aluminum silicates, clays, quartz, etc., identified experimentally. PHREEQC can model desalination to predict scale problems, allowing for early decision-making.

Influence of pulsed and alternating flow on the filtration performance during skim milk microfiltration with flat-sheet membranes

Control of deposit formation during skim milk microfiltration (MF) remains challenging, particularly in membranes with spacer nets between membrane layers like flat-sheet and spiral-wound membranes, due to the extensive occurrence of flow shadows behind spacer filaments. One approach to improve process control and efficiency is applying pulsed or alternating flow, which creates regular fluctuations in shear stress, pressure and, for alternating flow, in flow direction. This study assessed the effects of these alternative flow types and compared them to conventional steady crossflow on deposit formation and filtration performance. Flux and protein permeation were monitored during filtration. After filtration, the membranes were removed and deposited proteins stained by Coomassie-blue. The visual analysis of the stained membranes confirmed that the alternative flow types improved access to flow shadows behind spacer filaments by causing a significantly reduced deposition or enhanced removal. Consequently, the reduced deposit formation with pulsed and alternating flow led to enhancements in the steady-state whey protein mass flow by > 8% and > 37% over any steady flow conditions. Considering the flow-specific pump energy demands, pulsed and alternating flow not only improved filtration performance, but also reduced specific energy consumption relative to whey protein mass transfer by > 60%.

Transmembrane Pressure during Micro- and Diafiltration of Milk Affects the Release of Non-Sedimentable Caseins.

Membrane filtration, especially in combination with diafiltration, can affect the colloidal structure of casein micelles in milk and concentrated milks. The partial dissociation of casein proteins from the casein micelles into the serum phase has been shown to depend on diafiltration conditions. This dissociation can affect the technological functionality of the milk concentrates. The present study aimed at determining the contribution of the gel layer deposited onto the membrane during filtration in the colloidal equilibrium between soluble and micellar caseins. Skimmed milk was concentrated by microfiltration combined with diafiltration using a cross-flow spiral-wound membrane at two transmembrane pressure (TMP) levels, causing differences in the extent of the gel layer formed. Non-sedimentable casein aggregates were formed to a greater extent at a low TMP compared to a high operating TMP. This difference was attributed to the greater compression of the deposit layer during filtration at a high TMP. This study contributes new knowledge to the understanding of how to modulate the functionality of milk concentrates through the control of processing conditions.

Optimizing UVC-disinfection using LEDs as an energy efficient pre-treatment for biofouling control in spiral-wound membrane systems

Biofouling remains a major challenge for reverse osmosis (RO) systems. Pulsed ultraviolet (UV) pre-treatment has been proposed as a mitigation strategy for biofouling control of RO membranes. This study investigated whether increasing fluence rate during pulsed UV disinfection leads to enhanced inactivation. Further, UV irradiation from 1.5 to 61.3 mJ cm−2 was tested for optimal biofouling control. Therefore, an UVC-LED reactor was characterized by successfully adapting an actinometry method for flow-through mode. The inactivation of microorganisms was compared in flow-through biodosimetry experiments in pulsed and continuous irradiation. Finally, several settings were applied as pre-treatment in lab-scale biofouling experiments and membrane performance and biofilm removability elucidated. Whereas no enhanced inactivation was observed during biodosimetry experiments, pulsed UV disinfection resulted in an average of 20.6 % increased delay of biofilm formation. On the contrary, for pulsed UV disinfection, the biofilm hydraulic resistance seemed higher than continuous equivalents, but not significantly. Overall, savings of operational expenditures per fluence applied was highest around 4 mJ cm−2. UV pre-treated biofilms showed no enhanced removability, but delay in biofilm formation was noticeable in two of three experiments. In case the effects translate to up-scaled applications over several cleanings, UV pre-treatment for biofouling control is an interesting option.

Comparison of the efficiency of pulsed flow membrane cleaning in hollow fibre (HFM) and spiral-wound microfiltration membranes (SWM)

Membrane cleaning is a particular issue for spiral-wound membranes (SWM), as their cleanability is limited due to spacer-induced flow shadows behind spacer filaments. One option to enhance membrane cleaning efficiency is applying pulsed flow, characterised by a cyclic transition between high and low flow rates. This study examined how the cleaning success in hollow fibre membranes (HFM) and spiral-wound membranes (SWM) can be enhanced by pulsed flow at varying concentrations of the cleaning agent NaOH. The cleaning success was determined by protein removal and flux recovery analyses as well as scanning electron microscopy (SEM) imaging of cleaned membrane surfaces. The highest increase in cleaning efficiency as a result of pulsed flow was found for SWM at cNaOH = 0.03% (pH 11.3), where protein removal was increased by 48% over steady flow cleaning. SEM analyses confirmed that this was due to the pulsation-induced turbulence allowing improved access to spacer-induced flow shadows. Overall, cleaning success with pulsed flow at cNaOH = 0.03% could be improved in both HFM and SWM over that of steady flow at cNaOH = 0.30%, implying distinct reductions in chemicals consumption or shortened cleaning times when applying pulsed flow.

Evaluation of Commercial RO Membrane for BaCl2 Separation

The conventional methods of the BaCl2 solution separation are characterized by high energy consumption, reagent requirement, and other technological limitations. The pressure-driven membrane process can be an alternative, but the number of published investigations in this field is limited. The study of the effectivity of the BaCl2 diluted solution separation using the commercially available reverse osmosis membrane was carried out. It was defined that the spiral wound membrane module HID TFC 1812-75 GPD (nominal permeate flux is 281 l/d) has acceptable characteristics of productivity and selectivity. In particular, the permeate flux through these membranes for the BaCl2 solutions does not differ from the fluxes for other salt solutions in the considered range of the applied pressures (0.2-0.6 MPa). The rejection coefficient values were in the range of 0.9-0.95 and slightly varied with applied pressure. Therefore, such membranes are suitable for wastewater purification from the remains of BaCl2. At the same time, the concentration ratio does not exceed 1.5-2, consequently, the application of such membranes on the concentration stage requires deeper justification based on the economical parameters. The significant influence of the concentration polarization on the separation effectivity was not detected up to applied pressures 0.5 MPa.