Rotating Disk Module Research Articles

Rotating Disk-Assisted Cross-Flow Ultrafiltration of Sugar Beet Juice

Rotating disk module (RDM)-assisted cross-flow ultrafiltration of sugar beet juice, obtained by cold pulsed electric field-assisted pressing, was studied in full recycling and concentration modes. Results of trans-membrane pressure (TMP) stepping tests with 10- and 50-kDa membranes showed that filtration flux increased with rotation speed and TMP until 1000 rpm and 4 bar. A slight variation of filtration purity was observed for a rotation speed range of 0–2500 rpm. A TMP increase resulted in purity reduction due to the formation of thicker fouling layer. A full recycling test study with a 10-kDa membrane confirmed the influence of TMP and rotation speed on filtration flux. A rotation speed of 1000 rpm and a TMP of 4 bar were selected for sugar beet juice purification, by concentrating juice from 13 to 1 L. The results of concentration mode tests revealed that, with a 10-kDa membrane, the filtrate purity could reach 95.6 ± 0.5 %, which was comparable to the purity of sugar beet juice purified by conventional liming-carbonation method. The flux decline in cross-flow filtration was still important, justifying more effective anti-fouling technologies investigation.

Leaf protein concentration of alfalfa juice by membrane technology

Membrane technology (microfiltration (MF) and ultrafiltration (UF)) of alfalfa juice was studied as an alternative method to conventional leaf protein concentration. Three types of filtration modules (dead end filtration using laboratory Amicon cell (DA), dynamic cross filtration using rotating disk module (CRDM) and dead end filtration using rotating disk module (DRDM)) were used to investigate concentration efficiency of MF and UF with full recycling tests and concentration tests. Rotating speed and transmembrane pressure (TMP) improved flux behavior, but higher permeate flux caused by higher rotating speed reduced leaf protein rejection of MF. The strong rotating shear effect and open flow channel structure of CRDM could control concentration polarization and membrane fouling, therefore, it gave the best flux behavior, least flux decline, best clarification effect, smallest irreversible fouling and highest permeability recovery in membrane cleaning. However, the best leaf protein rejection was obtained by DRDM, because of high shear rate and “secondary filtration” of fouling layer created by closed flow channel structure. Besides, CRDM showed the highest productivity and best potential for industrial application. These results from laboratory-scale tests can be very useful for concentrating leaf protein from alfalfa juice and serve as a valuable guide for process design in industrial scale.

Dead-End Dynamic Ultrafiltration of Juice Expressed from Electroporated Sugar Beets

Membrane dead-end ultrafiltration of sugar beet juice (obtained from pulsed electric field assisted nonthermal pressing) was studied as an alternative method to the conventional liming-carbonation purification. A dead-end filtration module, Amicon 8200, was first used to investigate the purification efficiency of ultrafiltration with various polyethersulfone membranes (10 kDa, 50 kDa, and 150 kDa). The purity of sugar beet juice was increased from 93.6 ± 0.5 to 96.4 ± 0.8 % with a 10-kDa membrane. In order to improve the filtration flux, which declined tremendously during dead-end filtration due to membrane fouling, a rotating disk module (RDM) was then applied, and the investigation of the dynamic filtration behavior and filtrate quality of sugar beet juice was carried out. Compared with Amicon stirred module, the RDM had a much higher permeate flux and filtrate purity. The effect of rotating speed and molecular weight cutoff (MWCO) of membranes were studied. The permeate flux increased with rotating speed and pore size of membrane. The permeate flux increased significantly when the rotating speed was raised from 500 to 1,000 rpm, while it slightly increased at higher rotating speed (2,000 rpm). The purification efficiency of dynamic RDM filtration was about twice than that of filtration performed with Amicon stirring module.

Study of rotating disk assisted dead-end filtration of chicory juice and its performance optimization

Inulin was extracted by pulsed electric fields (PEFs) assisted diffusion. Rotating disk module (RDM) assisted dead-end filtration of chicory juice was studied. Filtration behavior, flux decline and fouling coefficient of RDM assisted filtration were investigated and compared with the performance of previously used normal stirred filtration unit. Response surface methodology (RSM), based on a three levels and two variable central composite rotatable design (CCRD), was employed to obtain the best possible combination of trans-membrane pressure (TMP) (X1: 2–6bar), shear rate (X2: 12,000–102,000s−1) for maximum average flux and minimum specific energy consumption. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression and were also analyzed by variance analysis (ANOVA). The 3-D response surface and contour plots derived from the mathematical models were applied to determine the optimal conditions. The optimum filtration conditions were: a TMP of 3.34bars, and a shear rate of 102,000s−1. Under these conditions, the experimental average flux and specific energy were 154L/m2h and 169kwh/m3, respectively, which were in close agreement with the values predicted by the model. Results of this work may contribute to increase chicory juice filtration for inulin purification.

Flux behavior in clarification of chicory juice by high-shear membrane filtration: Evidence for threshold flux

Membrane fouling and flux decline are important problems in chicory juice clarification by membrane process for inulin production. In this study, a rotating disk module (RDM) equipped with four micro- and ultra-filtration membranes was used to treat raw chicory root extract, and the permeate flux behavior at high-shear conditions was investigated. Increasing disk rotating speed can reduce concentration polarization and cake fouling, and thus improve permeate flux. However, a moderate rotating speed of 1000rpm was a good compromise between energy saving and polarization/cake layers control, while a higher disk rotating speed can be used at regular intervals for on-line membrane cleaning. Threshold and limiting fluxes were determined in chicory juice clarification at 1000rpm and 50°C by pressure stepping experiments, and they were almost independent of pore size, permeability and fouling extent, with ranges of 130–140Lm−2h−1 for threshold and 155–168Lm−2h−1 for limiting flux. Below threshold flux, filtration resistance is independent of flux, while above it, membrane fouling increases with increasing permeate flux. This work confirmed that threshold flux criterion was also applicable to high-shear microfiltration and ultrafiltration, and size-dependent shear-induced and Brownian back diffusions played an important role in such filtration resistance transition. Moreover, both limiting flux and flux fluctuations should be avoided in practical applications because they cause high fouling and flux decline.

Chicory juice clarification by membrane filtration using rotating disk module

Clarification is the first step of inulin production from chicory juice, and membrane filtration as an alternative can greatly simplify this process, increase juice yield, improve product quality, and reduce the cost and waste volume. In this study, a rotating disk module (RDM) was used to investigate the clarification of chicory juice by four micro- and ultrafiltration membranes. Compared with dead end filtration, the RDM had a much higher permeate flux and product quality. High rotating speeds produced high permeate fluxes and reduced flux decline, because of the strong back transport of foulant from fouling layer to feed solution. At high rotating speeds of 1500–2000rpm, the permeate flux increased with membrane pore size and transmembrane pressure (TMP), while at low rotating speeds (<1000rpm), permeate flux was independent of membrane type and TMP due to a thick deposited fouling layer as a dominant filtration resistance, while carbohydrate transmission decreased at higher TMP because of denser cake layer as an additional selective membrane. The highest carbohydrate transmission (∼98%) and desirable permeate turbidity (2.4NTU) was obtained at a TMP of 75kPa and a rotating speed of 2000rpm for FSM0.45PP membrane. With the RDM, the Volume Reduction Ratio (VRR) could reach 10 with a high permeate flux (106Lm−2h−1) in the concentration test, and permeate was still rich in carbohydrate and well clarified. Chemical cleaning with 0.5% P3-ultrasil 10 detergent solution was able to recover 90% water flux of fouled membrane.

Treatment of dairy effluent by shear-enhanced membrane filtration: The role of foulants

Treatment of dairy effluent by membrane filtration permits to recover both reusable water and nutrients, but its advantages are weakened by concentration polarization and subsequent membrane fouling as they cause flux decline and permeate quality deterioration. In order to control flux decline, model dairy effluent was treated by shear-enhanced membrane filtration in this study, and the role of foulants was analyzed. For ultrafiltration (UF) of dairy effluent, protein adsorption and deposition caused flux decline and hydrophilic modification of membranes can reduced this fouling. While for nanofiltration (NF), flux decline was mitigated by the presence of casein micelles, and when the caseins were removed by UF pretreatment, whey proteins would agglomerate through calcium bridges, resulting in severe flux decline during NF concentration. Even if most of proteins were retained by UF pretreatment, free calcium ions increased due to the absence of casein micelles, also inducing flux decline at high concentration factor. Thus, the two-step UF/NF process was not found advantageous as it did not improve the average permeate flux nor permeate quality, while increasing significantly the process energy consumption. This conclusion was valid not only for rotating disk module (RDM) but also for vibratory shear-enhanced process (VSEP), which is available in large membrane area with a low energy consumption.

Flux decline control in nanofiltration of detergent wastewater by a shear-enhanced filtration system

Treatment of wastewater containing a cleaning-in-place detergent was investigated by using a rotating disk module equipped with a nanofiltration (NF) membrane. At a rotational speed of 2000rpm, a pH 7.2 and 25°C, the permeate flux reached a plateau at 350Lm−2h−1 above 35bar while rejection of conductivity and COD were respectively 93 and 97%. When a pretreatment by ultrafiltration (UF) was carried out before the NF, the NF flux increased linearly with TMP to reach 450Lm−2h−1 at 40bar while COD of NF permeate was a little lower than without pretreatment. Both permeate flux and conductivity rejection increased with increasing pH. High membrane shear rates prevented flux decline with time, as surfactant molecules were dragged away from membrane surface, preventing surfactant aggregates formation. The disk rotational speed necessary for flux stability increased with TMP from 1000rpm at 10bar to 2000rpm at 30bar. Increasing feed pH had a similar effect by enhancing electrostatic repulsion between surfactant molecules and membrane. Raising the temperature to 45°C increased the permeate flux to over 500Lm−2h−1 at 30bar and 2000rpm. This work confirms the high performance of high shear dynamic filtration in detergent wastewater treatment by NF system both in terms of permeate flux and ion and COD rejections due to reduction in concentration polarization, so that a UF pretreatment was not necessary.

Comparison of permeate flux and whey protein transmission during successive microfiltration and ultrafiltration of UHT and pasteurized milks

This paper investigates whether UHT skim milk could be a valid fluid model for testing the separation of whey proteins from casein by microfiltration (MF) and of α-Lactalbumin (α-La) from β-Lactoglobulin (β-Lg) by ultrafiltration (UF). To this effect, we have measured permeate fluxes, α-La and β-Lg transmissions during MF concentration tests with pasteurized and UHT skim milks using a dynamic filtration module with rotating ceramic membranes. Then, wheys resulting from these permeates were ultrafiltered at 50 kDa with a rotating disk module while measuring permeate fluxes and α-La and β-Lg transmissions during concentration. Results showed that, in MF, permeate fluxes were slightly higher for UHT milk than for pasteurized milk. Student tests showed that, if α-La transmissions were slightly higher for UHT milk than for pasteurized milk, they were not significantly different. β-Lg transmissions were a little higher for UHT than for pasteurized milk. In UF tests, permeate fluxes were higher at low VRR (volume reduction ratio) for pasteurized whey, but decayed faster than for UHT milk when VRR increased. α-La and β-Lg transmissions in UHT whey were not significantly different from corresponding ones in pasteurized whey. These results show that the lower concentration of native whey proteins in UHT milk does not affect much their transmission and permeate flux, both in MF and in UF.

Fractionation of pasteurized skim milk proteins by dynamic filtration

Abstract This paper describes a two-stage process for separating milk proteins from pasteurized skim milk in three fractions: casein micelles, β-Lactoglobulin (β-Lg) and other large whey proteins, and α-Lactalbumin (α-La). Casein micelles were extracted in the retentate of a microfiltration using rotating ceramic disk membranes. α-La and β-Lg transmissions remained between 0.8 and 0.98. Their yields in permeate reached 81% for α-La and 76.6% for β-Lg at a VRR of 5.4. The separation between β-Lg and α-La was carried out by UF using a rotating disk module equipped with a 50 kDa PES circular membrane. Permeate fluxes were very high, remaining above 340 L h−1 m−2 at VRR = 5 and 40 °C. α-La transmission remained generally between 0.2 and 0.13 giving yields from 28% to 34%. β-Lg rejection was above 0.94, giving a maximum selectivity of 4.2. These data confirm the potential of dynamic membrane filtration for separating α-La and β-Lg proteins from skim milk.

Separation of casein from whey proteins by dynamic filtration

It has been proven that functional properties of milk proteins can improve the quality and nutritional value of foods. This paper investigates the separation of whey proteins from casein micelles using a Multi Shaft Disk (MSD) module and a rotating disk dynamic filtration module. The MSD module was equipped with 6 ceramic membranes of 0.2 µm pores. PVDF and Nylon membranes of 0.2 µm pores were tested in the rotating disk module. Permeate flux with the MSD module increased with TMP and rotation speed, reaching a maximum of 132 L h − 1 m − 2 at 1931 rpm. α-Lactalbumin (α-La) and β-Lactoglobulin (β-Lg) transmissions also increased with rotation speed, ranging from 25% at 1044 rpm to 40% at 1931 rpm . With a Nylon membrane, the rotating disk module yielded lower permeate fluxes than the MSD module, while when equipped with a PVDF membrane it provided higher permeate fluxes than the MSD, but casein micelles rejection was lower. α-La and β-Lg transmissions were higher with the rotating disk module, using Nylon and PVDF membranes, than for the MSD. From this comparison, it can be concluded that the MSD module gave the best compromise between high permeate flux, high α-La and β-Lg transmissions and high casein micelles rejection.

Recovery of linseed oil dispersed within an oil-in-water emulsion using hydrophilic membrane by rotating disk filtration system

The purpose of this paper is to investigate a method to recover the linseed oil from oil-in-water (O/W) emulsion by a rotating disk filtration system. The influence of transmembrane pressure (TMP), disk rotating speed, and disk geometry on permeate flux and oil recovery has been studied. Hydrophilic polyvinylidene difluoride (PVDF) membranes with average pore size 0.15 μm and polyethersulfone (PES) membranes with 50 kDa molecular weight cut off (MWCO) were used. The results showed that the rotating disk module can produce high permeate fluxes. The highest permeate fluxes were obtained when using a rotating disk equipped with vanes, which generated the largest shear rates at the membrane. This study demonstrated that hydrophilic membranes were suitable for demulsification of linseed oil-in-water emulsion. The linseed oil droplets in the emulsions could be separated by concentration tests due to the coalescence of oil droplets in the concentration polarization layer. For an initial oil mass of 46.5 g, 35.2 g supernatant oil was obtained owing to oil droplets coalescence. This supernatant oil represented a recovery of 76%. The rotating disk with vanes consumed less specific energy than smooth disk in the concentration tests.

Separation of casein micelles from whey proteins by high shear microfiltration of skim milk using rotating ceramic membranes and organic membranes in a rotating disk module

This paper investigates the microfiltration of skim milk in order to separate caseins micelles from two whey proteins, α-lactalbumin (α-La) and β-lactoglobulin (β-Lg), using a modified dynamic filtration pilot (MSD) consisting in 6 ceramic 9-cm diameter membrane disks of 0.2 μm pores, rotating around a shaft inside cylindrical housing. A comparison was made with another dynamic filtration module consisting in a disk rotating near a fixed PVDF 15.5 cm diameter membrane with 0.15 μm pores. Maximum permeate fluxes were 120 L h−1 m−2 with the MSD module at 1930 rpm and at 40 °C, and 210 L h−1 m−2 at 2500 rpm and 45 °C, with the rotating disk module. Casein rejection was around 99% at high speed for both membranes. α-La transmission decreased with increasing transmembrane pressure (TMP) from 75% to 60% for ceramic membranes and from 25% to 10% for the PVDF one. β-Lg transmissions were lower, ranging from 23% to 15% for ceramic membranes and from 20% to 5% for the PVDF one. In a concentration test with the PVDF membrane at 2000 rpm, the flux decayed from 200 L h−1 m−2 at initial concentration to 80 L h−1 m−2 at VRR = 3.2 and 22.1% of the initial α-La mass was recovered in the permeate, against 8.1% for β-Lg. Permeate fluxes in the mass transfer limited regime (Jlim) of the MSD and rotating disk module operated at various speeds were well correlated by the equation Jlim = 17.13 Vav where Vav denoted the disk azimuthal velocity averaged over the membrane area. Measurements of Jlim, taken from Ref. [G. Samuelsson, P. Dejlmek, G. Tragardh, M. Paulsson, Minimizing whey protein retention in crossflow microfiltration of skim milk. Int. Dairy J. 7 (1997) 237–242] during MF of skim milk using tubular ceramic membranes at velocities from 1.5 to 8 m s−1 with permeate co-current recirculation were found to obey the same correlation.

Comparison between rotating disk and vibratory membranes in the ultrafiltration of oil-in-water emulsions

The purpose of this work is to compare the effects of hydrodynamic parameters on the permeate flux provided by two different dynamic filtration systems using same membrane material and same fluids. Tested systems were rotating disk module and a VSEP pilot with a circular vibrating membrane. Test fluid consisted of oil in water emulsion of cutting fluid. The characteristic shear rate was taken to be the maximum one at the membrane. It was varied by changing the rotation speed of the disk or by changing the vibration frequency of the VSEP. The highest permeate fluxes were obtained with rotating disks equipped with vanes. With the VSEP, the flux decreases with time. However, the fouling limitation disappears completely for a disk equipped with vanes. In the two systems, the flux is mainly governed by the maximum shear rate and not by details of internal flow and can be increased to very high levels by increasing rotation speed or vibration amplitude.

Extraction of oligoglucuronans of low degrees of polymerisation from a fermentation broth by cascade filtration using a rotating disk module

We have investigated the extraction of oligosaccharides produced by enzymatic degradation of a bacterial polysaccharide obtained by fermentation of Sinorhizobium meliloti bacteria. We have used a cascade of ultrafiltrations and nanofiltrations with a rotating disk module in order to separate oligoglucuronans of degrees of polymerisation between 3 and 7, which have interesting medical properties. This work confirms the high performance of rotating disk system for the fractionation of complex biotechnological solutions.

Studies on ultrafiltration of casein whey using a rotating disk module: effects of pH and membrane disk rotation

In this study, a detailed analysis of protein fractionation from casein whey using two-stage ultrafiltration (UF) with 30 kD and 10 kD flat-disk membrane in stirred rotating disk module has been made with an objective to understand the effect of membrane rotation and other important parameters on permeate flux and rejection. The membrane rotation was found to enhance the flux and was highly efficient in reducing the concentration polarization. The other independent variables being studied were solution pH, trans-membrane pressure (TMP) and stirrer speed. In the first stage UF with 30 kD membrane, most of the bovine serum albumin (BSA), lactoferrin (Lf) and immunoglobulin (Ig) were found to be rejected, and in the other with 10 kD membrane, α-lactalbumin (α-La), β−lactoglobulin (β-Lg) were rejected to give clear permeate with low protein concentration. To understand the effect of pH on whey protein UF, all the UF runs were taken at two different pH levels, 2.8 and 5.7, with 4.6 being isoelectric point (pI) of the casein. The effect of monomer-dimer equilibrium at higher pH has been observed and investigated. At feed pH 2.8 and membrane rotation at 300 rpm or more, higher fluxes were observed within the TMP range of 4–5 kg/cm 2. A 75.1% β-Lg purity (on total protein basis) was obtained in the final stage, i.e. in 10 kD retentate at a TMP of 4 kg/cm 2 in stirred rotating disc module with 600 rpm membrane rotation speed.

Treatment of dairy process waters modelled by diluted milk using dynamic nanofiltration with a rotating disk module

We have investigated the recovery by nanofiltration of lactose and milk proteins as well as carbon oxygen demand (COD) and ionic concentration reduction in dairy process waters simulated by UHT skim milk diluted 1:2 with an initial COD of 36,000 mgO 2 L −1. The filtration system consisted in a 14.5 cm diameter metal disk (smooth or equipped with vanes) rotating near a circular Desal 5 DK membrane. At initial concentration, the permeate fluxes at a transmembrane pressure (TMP) of 4000 kPa and 45 °C ranged from 130 L h −1 m −2 for a smooth disk at 1000 rpm to 230 L h −1 m −2 using a disk with vanes at 2000 rpm. Permeate COD was minimum for this last case which gave the highest shear rates and decreased with increasing TMP from 60 mgO 2 L −1 at 1400 kPa to 22 at 4000 kPa. In concentration tests at a TMP of 4000 kPa, at 2000 rpm with vanes, the permeate flux decayed with increasing volume reduction ratio (VRR) but was still 100 L h −1 m −2 at VRR = 7.5. The maximum VRR, reached using a disk with 6 mm vanes rotating at 2000 rpm, was 14.3, corresponding to 38% of dry matter. Permeate COD remained quasi independent of shear rate (rotation speed and disk type) until VRR = 5 but increased more rapidly at lower shear rates for higher VRR, to reach 350 mgO 2 L −1 at 2000 rpm with vanes. Comparison with recent data using same fluid, and same membrane, but installed in a vibrating system (VSEP), showed that the rotating disk yields better performance than the VSEP, due to its higher membrane shear rate.

Investigation of performances of a multishaft disk (MSD) system with overlapping ceramic membranes in microfiltration of mineral suspensions

This paper investigates a new design of dynamic filtration system which has become recently available. The pilot unit tested contains 12 ceramic membrane disks with 0.2 μm pores, 9.0 cm in diameter, mounted on two parallel shafts rotating in the same direction at the same speed and surrounded by a steel housing. The fluid is sheared between overlapping disks. The differential speed (DV n) between two adjacent disks has been shown to be uniform in the overlapping region and 51% higher than the azimuthal rim speed of a disk. Test fluids were CaCO 3 suspensions at various concentrations ranging from 100 to 280 g L −1 and 24 °C. Permeate fluxes obtained at 1930 rpm (DV n = 13.47 m s −1) and 200 kPa were very high, ranging from 880 L h −1 m −2 at 100 g L −1 to 720 L h −1 m −2 at 280 g L −1. At 738 rpm (DV n = 5.25 m s −1), these fluxes were respectively, 690 and 430 L h −1 m −2. When a system with rotating membranes is operated at a fixed inlet pressure, its permeate flux rises with increasing speed until it reaches a maximum and decreases at higher speed, due to build-up of permeate pressure caused by centrifugal forces, which reduces the transmembrane pressure. In our pilot, this phenomenon was only observed at low inlet pressures. Rotation speeds at which a maximum flux occurred were 800 rpm at 40 kPa and 1600 rpm at 75 kPa. A comparison with a single rotating disk module, using an identical stationary ceramic membrane and the same test fluids, has shown that, for the same disk azimuthal rim velocity, permeate fluxes in this case were about half of those with the two-shaft pilot.

Studies on the fractionation of β-lactoglobulin from casein whey using ultrafiltration and ion-exchange membrane chromatography

The objective of this work is to obtain a relative separation of β-lactoglobulin (β-LG) from whey protein concentrate by fractionation of protein using two-stage ultrafiltration (UF) with 30 and 10 kg mol −1 molecular weight cut-off (MWCO) flat-disk membranes in stirred rotating disk module followed by ion-exchange membrane chromatography (IEMC) using Vivapure™ Q Mini-H column. Prior to UF, centrifugation, microfiltration and a four-stage discontinuous diafiltration (DD) were carried out to obtain whey protein concentrate from raw casein whey. Centrifugation and microfiltration were carried out to remove the major foulants like colloidal matters, suspended casein particles and lipid. DD using 5 kg mol −1 polyethersulphone (PES) membrane with volume concentration ratio (VCR) 2 in each stage was employed with an objective to enrich the whey proteins by removing most of lactose, minerals and salts. The effects of various parameters, like solution pH, trans-membrane pressure (TMP), stirrer speed and membrane rotation speed on UF flux and rejection were studied thoroughly. A 36% higher flux was obtained with a feed pH of 2.8 compared to that at pH of 5.6 at a fixed TMP of 5.0 × 10 5 Pa which has been explained with the help of the effect of pH on monomer–dimer equilibrium of β-LG and prevailing protein charge. A 33% enhancement of flux was observed at 1 min with membrane disc rotating at 300 rpm compared to the corresponding value of stationary membrane due to reduction in concentration polarization, the main limiting phenomenon for flux decline. A suitable loading buffer pH was investigated during IEMC runs so as to get a facilitated transport of β-LG over α-LA through the strong anion exchanger membrane. An 87.6% purity of β-LG (on total protein basis) was obtained in the filtrate of ion-exchange membrane chromatography.

Performance study during ultrafiltration of Kraft black liquor using rotating disk membrane module

Kraft processes require a large volume of water and accordingly a substantial amount of spent liquor; known as black liquor (BL) is produced. Attempts have been made in this study to analyze the performance of BL ultrafiltration using batch stirred rotating disk module. The flux enhancement and the reduction of concentration polarization phenomena have been observed with membrane rotation in this shear enhanced dynamic filtration and correlations have been drawn with different operating variables like transmembrane pressure (TMP), stirrer speed and membrane rotation speed. The rejection of solutes, mostly lignin and lignosulfonates has also been correlated with different operating parameters. Pretreatment centrifugation, followed by microfiltration has been used to remove traces of suspended solids to minimize the chances of membrane fouling. These pretreatment steps proved to be highly efficient in restoring the water flux completely in all the cases of experimentation. The work in this paper was done with specific emphasis on the environmental aspects; accordingly the effect of ultrafiltration on different variables like BOD, COD, oil and grease, total solids, turbidity, etc has been monitored in detail and the reduction in each of these parameters was correlated with different operating variables. Asymmetric cellulose triacetate membrane of 5000-molecular weight cut-off was used for the purpose of experimentation. A very good reduction in each of the aforementioned water quality parameters was observed. The research documented that ultrafiltration of BL with necessary pretreatment can produce good, disposable quality, water and on the other hand it can also provide a sound method for recovery of lignin.