Spiral Wound Configuration Research Articles

Performance Analysis of Reverse Osmosis Desalination Plant, Study Case of BBRI Plant

Desalination using seawater resources has been a cornerstone in meeting both human and industrial water demands for several decades. Some well-known methods are thermal desalination and membrane desalination. Among these, membrane desalination stands out, employing reverse osmosis (RO) technology, wherein seawater is pressurized and forced through a semi-permeable membrane to produce purified water. Black Bear Resources Indonesia (BBRI), which operates in the chemical industry relies on RO technology to cater its desalination requirements within the manufacturing facility. Notably, BBRI's desalination plant is equipped with both Seawater Reverse Osmosis (SWRO) and Brackish Water Reverse Osmosis (BWRO) modules. In the SWRO unit, the Hydranautic SWC-6 Max membrane is employed, while the BWRO unit features the Hydranautic ESPA-2 LD membrane. Both modules adopt the spiral wound configuration utilizing polyamide composite material. To determine the reliability of factory operations and dependability, a comprehensive performance analysis of the SWRO and BWRO units is imperative. This analysis encompasses critical parameters such as Recovery Rate, Membrane Flux, Percent Rejection, Concentration Rejection, and Specific Energy Consumption (SEC). Notably, performance degradation in both SWRO and BWRO systems primarily stems from membrane fouling, scaling phenomena, and the natural aging of the membranes.

Integration of Pre-Treatment with UF/RO Membrane Process for Waste Water Recovery and Reuse in Agro-Based Pulp and Paper Industry

This recent study aims to evaluate the efficacy of membrane filtration on recovery of water resource from agro-waste such as bagasse, crop-based pulp and paper mill waste. A mini pilot scale membrane system having a combination of pre-treatment filter unit (pre-filter, sediment filter and pre-carbon filter), ultra-filtration and reverse osmosis with spiral wound configuration were employed to evaluate the water reuse efficacy of effluent coming from the secondary clarifier of the conventional treatment plant of the mill. The operational conditions were optimized using Taguchi method at pH 8, temperature 32 °C, and pressure 2 bar and a flow rate of 60 l/hr. The qualities of the effluent from the secondary clarifier, and the permeate from both the combination, viz. Combination 1 (pre-treatment + ultra-filtration) and Combination 2 (pre-treatment + ultra-filtration+ reverse osmosis) were analyzed and the percentage reduction in pH, TDS, TSS, BOD, COD, Color, Lignin, Potassium and Sodium were calculated. The elimination of TDS, COD and BOD with Combination 1 was not promising (<22%). However, the installation of a RO membrane greatly reduced (>88%) the contaminants in both paper mill effluents. The obtained qualities of water from all the combinations were compared with the tolerance standard for reuse as process water. The quality of effluent from the secondary clarifier did not agree with any class of water quality. The permeate from the combination of pre-treatment and UF sufficiently reduced the TSS to reach the requirement. However, the combination of (pre-treatment + UF + RO) adequately complied with the quality standard required for reuse in the making of all grades of paper.

Advances and Applications of Hollow Fiber Nanofiltration Membranes: A Review.

Hollow fiber nanofiltration (NF) membranes have gained increased attention in recent years, partly driven by the availability of alternatives to polyamide-based dense separation layers. Moreover, the global market for NF has been growing steadily in recent years and is expected to grow even faster. Compared to the traditional spiral-wound configuration, the hollow fiber geometry provides advantages such as low fouling tendencies and effective hydraulic cleaning possibilities. The alternatives to polyamide layers are typically chemically more stable and thus allow operation and cleaning at more extreme conditions. Therefore, these new NF membranes are of interest for use in a variety of applications. In this review, we provide an overview of the applications and emerging opportunities for these membranes. Next to municipal wastewater and drinking water processes, we have put special focus on industrial applications where hollow fiber NF membranes are employed under more strenuous conditions or used to recover specific resources or solutes.

Modelling of arsenic (III) removal from aqueous solution using film theory combined Spiegler-Kedem model: pilot-scale study.

Arsenic contamination in drinking water is recognized as major health hazard worldwide. As reported in literature, more than 19% Indians are consuming lethal levels of arsenic for drinking purposes. In this work, arsenic (III) removal was studied using HFN300 polyethersulfone nanofiltration membrane in spiral wound configuration. Various membrane parameters such as hydraulic permeability (4.87Lm-2h-1bar-1), mass transfer coefficient (0.957*10-6ms-1), reflection coefficient (0.9), and solute permeability (2*10-9ms-1) were estimated using film theory combined Spiegler-Kedem (FTCSK) model. The higher value of reflection coefficient suggested the impervious nature of nanofiltration (NF) membrane used for arsenic (III) solute rejection. The influence of various operating parameters such as transmembrane pressure, initial feed concentration, and feed flowrate on membrane performance was also examined. It was found that arsenic (III) rejection was dependent on pressure and feed concentration. Result showed that more than 96.4% arsenic (III) rejection was achieved for 50mgL-1 of feed at optimized conditions. As HFN300 membrane was negatively charged at pH 8 and arsenic (III) was available in neutral solute form, electro-migration was not considered for solute rejection mechanism. Solution diffusion with significant coupling between solute and solvent, steric hindrance effect, convection, and solute-membrane affinity interactions were considered dominant factors for the possible solute rejection mechanism. Rejection efficiency (% R) and permeate flowrate (Q2) were simulated and compared with experimental results. It was found that simulated results were in excellent agreement with the experimental results. The maximum error obtained was within 10% for both % R andQ2. This confirms the efficacy of FTCSK model in predicting arsenic (III) removal using NF membrane. The annualized cost per cubic metre of treated water was estimated as 3.32 $/m3. This further confirms the feasibility of using NF process in removing arsenic from contaminated water.

Coupling Ultrafiltration-Based Processes to Concentrate Phenolic Compounds from Aqueous Goji Berry Extracts.

In this work, a membrane-based process for the purification and concentration of antioxidant compounds from aqueous Goji (Lycium barbarum L.) berry extracts was investigated. The aqueous extract was previously clarified with hollow fiber ultrafiltration (UF) membranes in order to remove suspended solids and β-carotene and to produce a clarified extract enriched in phenolic compounds. Then, three UF flat sheet polyamide membranes with a molecular weight cut-off (MWCO) in the range 1000–3500 Da were tested to purify and concentrate phenolic compounds from the clarified extract. The effect of MWCO and transmembrane pressure (TMP) on the performance of selected membranes in terms of productivity and selectivity towards total dissolved solids (TDS), total phenolic compounds (TPC), total carbohydrates (TC) and total antioxidant activity (TAA) was evaluated. Experimental results indicated that the 2500 Da membrane exhibited a lower fouling index, higher cleaning efficiency, lower rejection towards carbohydrates (lower than 30%) and higher rejection towards phenolic compounds (higher than 50%) in comparison to the other investigated membranes. The inclusion of a diafiltration process in the treatment of the clarified extract with this membrane in a spiral-wound configuration improved the concentration of sugar compounds in the permeate stream and increased the purification of phenolic compounds in the retentate fraction.

Pilot scale concentration of cheese whey by forward osmosis: A short-cut method for evaluating the effective pressure driving force

Cheese whey was concentrated to a concentration factor of 2.7 in a pilot scale forward osmosis filtration system, using a commercial cellulose triacetate membrane in a spiral-wound configuration. The whey was concentrated in a batch mode, using sodium chloride as the draw solution at initial osmotic pressures of 53–75 bar. During the process, flux was shown to reduce due to the simultaneous decrease in the bulk osmotic pressure of the draw solution, increase in the bulk osmotic pressure of the whey and the effect of concentration polarisation on both sides of the membrane. The flux is known to be driven by the effective osmotic pressures of whey and the draw solution on the surface of the membrane active layer. A short-cut approach that requires minimal information in advance about the osmotic pressure of whey and the geometry of the filtration system was implemented, enabling the determination of these effective osmotic pressures. The results obtained were shown to be in agreement with the fundamental forward osmosis flux model. The short-cut approach can be utilised for estimating effective osmotic pressures of other liquid food streams to be concentrated by forward osmosis, without the need of external measurements.

Development of intelligent system models for prediction of licorice concentration during nanofiltration/reverse osmosis process

Reverse osmosis (RO) and nanofiltration (NF) membranes in spiral wound configurations have been widely used in food processing ranging from dairy to fruit juice for concentration, purification and recovering valuable components. In this work, intelligent systems, i.e., back-propagation artificial neural network (BPNN), radial basis function (RBF), fuzzy inference system (FIS) and adaptive Neuro-fuzzy inference system (ANFIS) were employed to predict the water flux and solute rejection of RO and NF membrane during concentration of licorice solution. To develop the intelligent systems, normalized membrane type, temperature, pressure, pH and cross-flow velocity are taken as inputs while normalized permeate flux and rejection are as outputs of the models. The proposed intelligent systems have been compared based on statistical parameters of the coefficient of determination (R 2 ) and the mean absolute error (MAE). The results indicate that the ANFIS model is more accurate and reliable compared to the BPNN, RBF and FIS approaches. It was found that the predictions using ANFIS model were usually in good agreement with the experimental data, showing the R 2 values within the range of 0.932–0.997 and the MAE values in the range of 0.01–1.7%. On the basis of comparison among the results obtained from this investigation, it is suggested that the ANFIS model could be potentially utilized to forecast the rejection and permeate flux of membrane during the concentration process of a licorice solution.

Performance of Reverse Osmosis Membranes in the Treatment of Flue-Gas Desulfurization (FGD) Wastewaters

Reverse osmosis (RO) was studied to reduce salinity of flue gas desulfurization (FGD) wastewaters after softening with Na2CO3·H2O and ultrafiltration (UF). Two commercial thin film composite polyamide RO membranes (SWC-2540 and ESPA-2540, from Hydranautics) in spiral-wound configuration were tested and their performance in terms of salinity reduction as well as permeate flux, fouling index and water recovery was evaluated. Experimental runs were performed according to the feed and bleed configuration in selected operating conditions. For the SWC-2540 membrane experiments were also performed in total recycle configuration in order to evaluate the effect of operating pressure on permeate flux and quality. Experimental results indicated that the SWC-2540 membrane showed a better performance in the rejection of ions: Mg2+ ions were completely rejected, while the rejection towards monovalent ions such as Na+ was of about 95.5%. The ESPA-2540 membrane showed rejections towards Ca2+ and Mg2+ higher than 86.5% whilst the observed rejection towards Na+ was of 80%. For the SWC-2540 membrane an increased rejection for Ca2+ and Na+ ions was observed by increasing the operating pressure in the range 16-50 bar. Mg2+ ions were totally rejected independently by the operating pressure.

Evaluation of NF membranes as treatment technology of acid mine drainage: metals and sulfate removal

Acid mine drainage (AMD) are acidic streams rich in dissolved ferrous and non-ferrous metal sulfates and minor amounts of non-metals. Nanofiltration (NF) has been postulated as a potential technology in the metallurgical and mining industry to recover strong acids as H2SO4 and concentrate metallic ions from acidic mine waters. The performance of semi-aromatic polyamide (NF270) and sulfonated polyethersulfone (HydraCoRe 70pHT) NF membranes were evaluated at different trans-membrane pressures. Different synthetic solutions were filtered under spiral wound configuration at two pHs (2.0 and 2.8): i) a solution of Na2SO4 and ii) a solution mimicking AMD from dams, containing Na2SO4 and Fe2+, Zn2+ and Cu2+. NF270 showed metal rejections higher than 90%, while for HydraCoRe 70pHT they were in between 60 and 70%. Metal rejection values decreased when solution acidity was increased. Chemical composition of the membrane active layer and the aqueous metal-sulfate speciation were found to have a large impact on membrane separation process. Solution-Electromigration-Diffusion-Film model was used to estimate the membrane permeances to ions from the measured ion rejections. Furthermore, a full scale unit vessel containing six spiral wound membrane modules was simulated. NF270 showed a higher capacity for concentrating metal and sulfate ions (100%) than Hydracore 70pHT (50%).

Integration of MBR with NF/RO processes for industrial wastewater reclamation and water reuse-effect of membrane type on product water quality

In this study, some field tests were conducted at ITOB Organized Industrial Zone Wastewater Treatment Plant where membrane bioreactor (MBR) process has been used for wastewater treatment. The MBR treatment process provides stable and high quality product water but product water still contains high salinity in this case. Therefore, a mini-pilot scale membrane test system having three different nanofiltration (NF) which are NF90, NF270 and TR60 and two different reverse osmosis (RO) membranes which are BW30 and AG with spiral wound configurations was employed for demineralization of MBR effluent. The system was operated with 10 bar of operating pressure for NF membranes and at 20 bar for RO membranes. The average water recoveries of NF membranes were 50.2%, 56.0% and 51.8% for NF90, NF270 and TR60 membranes, respectively while average water recoveries of RO membranes were 64.0% for BW30 membrane and 62.3% for AG membrane. The qualities of product waters were analyzed and compared with standards to reuse them for agricultural irrigation and as process water. The permeates of NF270 and TR60 membranes agreed well with the third class water quality for salinity and the second class quality for the rest of parameters. On the other hand, the permeates of NF90, BW30 and AG membranes provided with the first class water for all parameters except for infiltration. Mixing the permeates of NF and RO membranes with MBR effluent in appropriate ratios was considered to be helpful to get acceptable quality values for product water and a good permeability for agricultural irrigation. Therefore, an optimum theoretical mixture of MBR effluent to permeates was determined. When qualities of product water obtained by NF and RO membranes were compared with the standards of cooling and boiling feedwaters for industrial usage and with the process water characteristics for pulp and paper, textile industries, it was considered that the permeates of NF90, BW30 and AG membranes obeyed well the quality standards required.

Comparative Assessment and Multivariate Optimization of Commercially Available Small Scale Reverse Osmosis Membranes

Requirement of reverse osmosis (RO) process at places facing energy and water quality problem makes its assessment and optimization vital while considering recovery, rejection as well as specific energy consumption. In the present paper, three thin film composite (TFC) RO membranes (make: CSM, Dow and Vontron) in spiral wound (SW) configuration have been chosen to study their relative performance. Comparative study of RO membranes was conducted using experimental observations supported by mem- brane characterization. Optimization experiments were performed using central composite design (CCD) of response surface metho- dology (RSM). Four input variables viz. feed water pH, temperature, pressure and concentration were optimized and interaction be- tween them was observed, while, recovery, rejection and specific energy consumption (SEC) were taken as response attributes. The experiments conducted employing the optimized input values validated the developed RSM model. Predictive model using multiple response optimization revealed the optimal efficiency of CSM RO membrane at 6.53 pH, 1500 mg/L concentration, 0.78 MPa pressure and 31.94oC temperature producing 19.25% water recovery, 89.21% salt rejection and 17.60 kWh/m3 SEC, respectively. Membrane surface characterization was carried out by FE-SEM, AFM, contact angle measurement and FTIR. The lesser contact angle and smoother surface apparently contributed to the better performance of CSM RO membrane. This paper may demonstrate a simple method for optimizing the commercially available small scale RO membranes.

Strategy for scale-up of SBS pervaporation membranes for ethanol recovery from diluted aqueous solutions

Abstract Ethanol is considered a green alternative to fossil fuels. Pervaporation (PV) is claimed to be an economical separation technique for ethanol recovery from fermentation broths. In this study, styrene-butadienestyrene (SBS) dense symmetric flat membranes were first prepared by solvent evaporation technique and applied for the pervaporative removal of ethanol from aqueous solutions. The results were compared with the performances of composite membranes made of SBS coated on a highly porous support of Fluoroplast F-42. In this case, an intermediate layer of PDMS (poly dimethyl siloxane) or PU (poly urethane) was used to improve the membrane performances. The results clearly evidenced the role of the intermediate layer (PU or PDMS) in improving the EtOH/H2O selectivity of the composite flat membranes in comparison to pure flat SBS membrane. Composite membranes were scaled-up in spiral-wound modules configuration and tested for the PV application of interest. A further increase in ethanol selectivity was observed (S.F.≈8) showing the superior performances of spiral wound modules with respect to their analogous membranes in flat sheet configuration. In all the PV tests carried out, the effect of ethanol concentration and feed temperature was investigated for each type of membrane.

Separating xylose from glucose using spiral wound nanofiltration membrane: Effect of cross-flow parameters on sugar rejection

A solution model consisted of two different monosaccharides namely xylose and glucose were separated using a pilot scale spiral wound cross-flow system. This system was equipped by a commercial spiral wound nanofiltration (NF) membrane, Desal-5 DK, having a molecular weight cut off (MWCO) of 150-300 g mol-1. The aim of this present work is to investigate the effect of the cross-flow parameters: the trans-membrane pressure (TMP) and the feed concentration (C0) on the xylose separation from glucose. The filtration experiments were carried out in total reflux mode with different feed concentration of 2, 5, and 10 g/L at different TMP of 5,8 and 10 bar. The performances of the NF membrane were evaluated by measuring the permeate flux and sugar rejection for each experiment. All the samples were quantified using a high performance liquid chromatography equipped by a fractive index detector. The experimental results indicated an increase in pressure from 5 to 10 bar which was a notable increase to the permeate fluxes from 2.66 × 10-3 to 4.14 × 10-3L m-2s-1. Meanwhile, an increase in the C0 increases the xylose rejection. At TMP of 10 bar and C0 of 5 g/L, the observed xylose rejection and glucose rejection were measured at 67.19% and 91.82%, respectively. The lower rejection in xylose than glucose suggested that larger glucose molecule were not able to easily pass through the membrane compared to the smaller xylose molecule. The results of this phenomena proved that NF with spiral wound configuration has the potential to separate xylose from glucose, which is valuable to the purification of xylose in xylose production as an alternative to chromatographic processes.

Will ultra-high permeance membranes lead to ultra-efficient processes? Challenges for molecular separations in liquid systems

An increasing number of reports in the scientific literature describe membranes with ultra-high permeance which might revolutionise molecular separations in liquid systems by making separation processes dramatically more efficient. Many of these reports relate to breakthroughs in materials science, including fabrication of new 2-D materials such as graphene oxide, and structured materials such as metal organic frameworks. Interestingly, the ultra-high permeances described are invariably measured for flat sheet membranes, in highly dilute systems. The effects of pressure gradients across the membrane, and the effects of concentration polarisation at significant, real world concentrations are not usually considered. In practise, membrane modules, rather than flat membrane sheets, are used in industrial processes. In concentrated systems, employing modules, concentration polarisation and module pressure drops will also affect overall process performance. This work examines the extent to which increasing membrane permeance can impact on processes employing membrane modules, considering both spiral-wound and hollow fibre configurations. Our key conclusion is that ultra-high permeance membranes will not be able to make a significant impact on process efficiency with current module designs; and our recommendation is that fresh research into module and process design is required.

Solar desalination by air-gap membrane distillation: a case study from Algeria

Experiments were conducted with a commercial membrane distillation module, which has an air-gap membrane distillation (AGMD) and spiral-wound configuration. Tests were performed simulating the salinity and temperature of the water using as a case study the Albian aquifer in Algeria. Solar thermal energy from a field of stationary flat-plate solar collectors was supplied to the module. The total productivity of the AGMD system was analyzed for different operational conditions and compared with that from the RO system. The effect of brackish water temperature on the energy consumption was scrutinized, and the energy requirements assessed toward the design of a pilot unit for decentralized autonomous solar desalination. Results showed that for producing a higher volume of distillate, module with less surface area is better. Also, it was found that recovery ratio increases linearly with the temperature difference in both modules. The maximum value was 6% for the highest feed flow rate operated in module 1 with highest surface area. These values are much lower than those obtained with RO processes, which can reach 45%.

Dry pressure drop in spiral wound wire mesh pads at low and elevated pressures

The dry pressure drops for 8 wire mesh pads were measured experimentally. The pads were of a spiral wound configuration and made of stainless steel wire. They ranged in porosities from 97.64% to 98.9% and with specific surface areas from 283m2/m3 to 593m2/m3. The range of heights was 50–150mm. A total of three fluid systems were used; One low pressure system using air at 1bar and two high pressures systems, nitrogen and natural, gas at pressures of 20, 50 and 85bars. The data were fitted to a modified Darcy–Hazen–Dupuit type equation, which included the specific surface area of the wire mesh pads, ΔPϵ2/(ρgUg2)=f(SL)+μgϵS2L/(ρgUg), with a mean standard deviation of ±5.3%. In addition a correlation encompassing literature data was developed with standard deviation of ±13.4%. A discussion is provided on the impact of specific surface area on dry wire mesh pad operation. Two other correlations for predicting dry pressure drop in wire mesh pads were also examined.

Application of nanofiltration membrane for treatment of chloride rich steel plant effluent

Composite charged nanofiltration membrane of polysulfone and zinc chloride was used to treat the effluent from TATA Steel, India. The effluent contained high amount of total solid and various ions, namely chloride (1000–1200mg/l), fluoride (140mg/l), nitrate (37mg/l) and phosphate (1730mg/l). The effluent was pre-treated by passing over granular activated carbon and total solid was reduced by 38%. The membrane containing 1wt% ZnCl2 was found to be optimized one. Chloride concentration was reduced below 800mg/l via charge–charge interaction by nanofiltration. Similarly fluoride, nitrate and phosphate ions were rejected around 32%, 27% and 70%, respectively. Effect of different operating conditions (transmembrane pressure, cross-flow rate and solution pH) was studied. Rejection of various ions and solid content was reduced with increase in transmembrane pressure and cross flow rate. Based on permeate flux and quality, 1380kPa and 80l/h cross flow rate were selected as optimum operating conditions. Simple in-situ washing of the membrane with tap water could recover permeate flux upto 97%. A resistance in series model was used to quantify the effects of polarization on system performance. This system can be scaled up in spiral wound configuration for final deployment.

Decolorization of Ionic Dyes from Synthesized Textile Wastewater by Nanofiltration Using Response Surface Methodology

Decolorization of aqueous solutions containing ionic dyes (Reactive Blue 19 and Acid Black 172) by a TFC commercial polyamide nanofilter (NF) in a spiral wound configuration was studied. The effect of operating parameters including feed concentration (60-180 mg/l), pressure (0.5-1.1 MPa) and pH (6-10) on dye removal efficiency was evaluated. The response surface method (RSM) was utilized for the experimental design and statistical analysis to identify the impact of each factor. The results showed that an increase in the dye concentration and pH can significantly enhance the removal efficiency from 88% and 87% up to 95% and 93% for Reactive and Acid dye, respectively. The effect of pressure on the removal efficiency showed different behavior such that by the raise of pressure from 0.5 to 0.8 MPa, the removal efficiency increased to its maximum, then reduction in removal efficiency was observed by further increases in pressure above the optimum range. The maximum dye removal efficiencies which were predicted at the optimum conditions by Design Expert software were 97 % and 94 % for Reactive Blue 19 and Acid Black 172, respectively. According to the results of this study, NF processes can be used at a significantly lower pressure and fouling issue for reuse applications as an alternative to the widely used RO process.

Modeling of flat-sheet and spiral-wound nanofiltration configurations and its application in seawater nanofiltration

The Donnan Steric Pore Model with dielectric exclusion (DSPM-DE) is implemented over flat-sheet and spiral-wound leaves to develop a comprehensive model for nanofiltration modules. This model allows the user to gain insight into the physics of the nanofiltration process by allowing one to adjust and investigate effects of membrane charge, pore radius, and other membrane characteristics. The study shows how operating conditions such as feed flow rate and pressure affect the recovery ratio and solute rejection across the membrane. A comparison is made between the results for the flat-sheet and spiral-wound configurations. The comparison showed that for the spiral-wound leaf, the maximum values of transmembrane pressure, flux and velocity occur at the feed entrance (near the permeate exit), and the lowest value of these quantities are at the diametrically opposite corner. This is in contrast to the flat-sheet leaf, where all the quantities vary only in the feed flow direction. However it is found that the extent of variation of these quantities along the permeate flow direction in the spiral-wound membrane is negligibly small in most cases. Also, for identical geometries and operating conditions, the flat-sheet and spiral-wound configurations give similar results. Thus the computationally expensive and complex spiral-wound model can be replaced by the flat-sheet model for a variety of purposes. In addition, the model was utilized to predict the performance of a seawater nanofiltration system which has been validated with the data obtained from a large-scale seawater desalination plant, thereby establishing a reliable model for desalination using nanofiltration.

A two-step nanofiltration process for the production of phenolic-rich fractions from artichoke aqueous extracts.

Commercial nanofiltration (NF) membranes in spiral-wound configuration (NP030 from Microdyn Nadir and Desal DK from GE Water & Process Technologies) were used in a sequential design in order to produce a separated fraction of phenolic and sugar compounds from an aqueous artichoke extract. For both membranes, the effect of transmembrane pressure (TMP) on the permeation flux was evaluated. In optimized conditions of TMP, the NP030 membrane exhibited high rejections of apigenin, cynarin and chlorogenic acid (higher than 85%); on the other hand, very low rejections of fructose, glucose and sucrose (lower than 4%) were measured. Starting from an extract with a total antioxidant activity (TAA) of 5.28 mM trolox a retentate fraction with a TAA of 47.75 mM trolox was obtained. The NF permeate from the NP030 membrane was processed with the Desal DK membrane in optimized conditions of TMP producing a permeate stream free of phenolic and sugar compounds. Accordingly, as most part of phenolic compounds was removed in the first NF step, the concentration of sugar compounds in the NF retentate had much higher results than that of phenolic compounds.