Backwashing Process Research Articles

Determination of Optimal Operation Pressure Values for Ultrafiltration Wastewater Treatment

The article presents results of research aimed to determine optimum operational modes of ultrafiltration membranes used to purify biologically treated wastewater as a pretreatment for further reverse osmosis desalination to produce water for industrial use. Results of experimental investigations are presented that evaluated influence of working pressure on operational costs. Optimum values of working pressure are determined for ultrafiltration treatment of wastewater with suspended solids concentrations 20 and 50 mg/L. A special respect is attributed to reduction of ultrafiltration membrane flux due to pore plugging during filtration cycle. Characteristics of membrane backwashing process are determined aimed on flushing-off all particles that plug membrane pores. Prognostic techniques are developed to predict reduction of ultrafiltration membrane flux due to pore plugging and schedule to apply additional membrane backwashes after flux reduces by 25 per cent at high-pressure values is proposed. Additional operational costs values are determined that account for increase of required membrane area and wash water to remove particles that plug pores.

A Hybrid Ion-Exchange Fabric/Ceramic Membrane System to Remove As(V), Zn(II), and Turbidity from Wastewater

Ceramic membranes and ion exchangers are effective at removing turbidity and ionic contaminants from water, respectively. In this study, we demonstrate the performance of a hybrid ion-exchange fabric/ceramic membrane system to treat metal ions and turbidity at the same time in synthetic wastewater. The removal rate of As(V) and Zn(II) by the ceramic membrane increased with solution pH, while turbidity was completely removed regardless of the solution pH. The main reaction of As(V) removal was adsorption at solution pH 6 and precipitation at solution pH 8, whereas phase-change was the predominant reaction for Zn(II) removal at both solution pH values. The removal efficiency of the ion-exchange fabric was affected by the solution pH, with the maximum removal capacity of As(V) occurring at solution pH 4. The As(V) adsorption capacity of the ion-exchange fabric reached equilibrium within 120 min. The ion-exchange capacity of the ion-exchange fabric was compared with commercial ion-exchange fibers. The regeneration efficiency of the ion-exchange fabric using 0.1 M NaCl solution was around 95% on average and decreased slightly as the number of regeneration cycles was increased. Over 80% of As(V) and Zn(II) were steadily removed at solution pH 6 by the hybrid ion-exchange fabric/ceramic membrane system. Reduced flow rate and removal capacity were recovered through a backwashing process during continuous treatment with the hybrid ion-exchange fabric/ceramic membrane system.

Backwashing behavior and hydrodynamic performances of granular activated carbon blends

Ozone-biological activated carbon (O3-BAC) process has been proved to be an efficient and cost-effective technology in advanced treatment of drinking water. However, O3-BAC raises strict requirements in adsorption, hydrodynamic and regeneration performances, which one single activated carbon could hardly all-sided meet. Blending activated carbons seems to be an appropriate and economically feasible method to deal with the issue. Thus, the uniformity and stability of activated carbon blends during water treatment, especially in backwashing process are of great importance. In this paper, cyclic experiments of downward adsorption and upward backwash on 11 typical commercial granular coal-based activated carbons and their blends were carried out in column test. Hydrodynamic performances such as bed expansion rate and bed pressure drop were measured. The uniformity and stability of activated carbon blends were investigated by determining iodine number of samples collected from different heights of activated carbon bed. Then, both traditional regression methods and back-propagation neural network model were utilized to predict superficial velocity at 30% bed expansion rate and maximum bed pressure drop of activated carbon blends. The results indicate that water backwashing process has no effect on the composition proportion of activated carbon blends, and slightly changes the particle distribution of activated carbon bed regarding pore structure and adsorption capacity. A three-layer back-propagation neural network model for superficial velocity at 30% bed expansion rate yields mean relative errors of 2.17%, which is much lower than that given by traditional regression methods such as 5.53% (weighted average), 4.08% (linear) and 4.06% (polynomial). Moreover, the back-propagation neural network model for maximum bed pressure drop yields mean relative errors of 1.37%, which is much lower than that given by traditional regression methods such as 4.31% (weighted average), 4.28% (linear) and 4.22% (polynomial). The non-linear relationships can be accurately identified by the back-propagation neural network model.

Hydraulic characterisation of the backwash process in sand filters used in micro irrigation

The objective was to evaluate effects of structural design, particle size and filter media height on pressure loss and surface velocity in the expanding filter layer during the backwashing process. The hydraulic behaviour of three commercial sand filter designs were compared. Experiments were conducted in an experimental closed circuit module. The treatments were based on the evaluation of three sand particle sizes combined with three filter bed heights for each filter design. The results showed that for the evaluated sand filters, with their different drainage structures in terms of area and arrangements, had different hydraulic behaviours during the backwashing. Coarser sand particles and greater filter layer heights produced larger slopes in the surface velocity curves as a function of percentage of filter bed expansion. No difference was observed in the minimum fluidisation velocity with changing the filter media heights, but an increase in the minimum fluidisation velocity was observed with increasing sand particle size. Filter beds composed of coarse sand particles and low filter bed heights produced lower increases in the pressure loss with increasing backwash surface velocity. Determining the minimum fluidisation velocity using the graphical analysis method to determine the pressure loss across the filter bed proved to be a reliable method for evaluating the equipment used.

Effect of wand-type underdrains on the hydraulic performance of pressurised sand media filters

Sand media filtration is frequently used in drip irrigation systems. Commercial filter designs may use different underdrain models but wand-type designs provide a large ratio of horizontal area covered by underdrains and are expected to provide a uniform flow of water through the medium. The complexity of these designs makes it difficult to analyse the effects of changing the position of wand and the slot open area. These underdrain effects were studied by means of a computational fluid dynamics (CFD) model assuming clean water conditions. The backwashing process was not considered. The CFD results were validated using experimental data from a commercial sand media filter with 10 wands. Unbalanced flows between underdrains were observed in the original configuration. Two new designs were proposed: (1) a design that uses the same type of wands as the original filter but distributes them so as to have an equal horizontal area served by each wand; (2) a design that uses the same spatial distribution as the original filter but with longer wands in those regions of the original filter with lower volumetric flow. CFD simulations indicate that design (1) can reduce the pressure drop through the filter at nominal volumetric flow rates by up to 5.8% with a more uniform flow inside the medium and design (2) could improve the performance of the filter by achieving an up to a 4.9% reduction of pressure drop. Thus, the spatial distribution of underdrains is a key parameter in the hydraulic performance of sand media filters.

Highly efficient nanofibrous sterile membrane with anti-BSA/RNA-fouling surface via plasma-assisted carboxylation process

Constructing a functional porous membrane scaffold for the efficient separation of bacteria from protein and nucleic acid drug stock solution remains a great challenge due to the permeability-selectivity trade-off and fouling propensity of membranes. Here, we adopted the nanofiber suspension coating approach to prepare sterile membrane with nanofiber coverage density of 6 g/m2. The carboxylation surface was further achieved through a facile route including alkaline solution activation and low temperature plasma treatment in sequence. As indicated by experimental and theoretical model analysis, nanofibrous membrane treated by alkali and plasma (NFM-APT) possess an ultrathin nanofiber active layer (about 4.7 μm), narrow pore size distribution (average size: 0.1 μm) and high hydrophilicity, which is beneficial for the absolute interception of E. coli, S. aureus and B. diminuta as well as a relative high and stable permeability (7400.4 L/(m2h), 0.2 MPa). Moreover, NFM-APT presents ultralow adsorption of BSA and RNA in the test of continue-flow and static-immersion modes with an excellent reusability after back-washing process, which is superior to the nascent nanofibrous membrane and commercially available PES membrane. The extraordinary anti-BSA/RNA-fouling performance can be attributed to the excellent hydrophilicity of membrane as well as the robust repulsive interaction between the negatively charged carboxyl group grafted on the surface of fiber and the negatively charged BSA&RNA. The NFM-APT also possesses outstanding performance stability, easy operation, and excellent recoverability. This work may provide a new avenue to design and develop next-generation high-performance sterile membrane for bio-separation.

What are the microscopic events during membrane backwashing?

Backwashing is an essential tool for sustainable filtration and is applied to remove particulate matter from membranes. Extensive experimental research has been carried out to improve the performance and efficiency of the backwash process. However, the essential microscopic events controlling backwashing on a membrane pore-scale level are far from being understood. Unraveling these pore-scale resuspension events of colloidal matter during backwash is challenging to comprehend and requires advanced non-invasive observation methodologies.First, this study applies microfluidic experiments that enable a pore-scale visualization of the resuspension events during backwash. The microfluidic experiments comprise two steps: a filtration and a backwash step. 4.2 μm polystyrene particles were filtered through a pore structure. After the pore structure is clogged, backwash is performed with varying flow rates. The experiments reveal that backwash is decisively controlled by particle clusters instead of single-particle effects. This clarifies that single-particle models are not representative of describing processes occurring during backwash.Second, multiphase simulations were conducted describing the interplay between hydrodynamic and colloidal interactions during particle resuspension. Two dominant events of backwash were identified from the simulations and the experiments: partial resuspension of particle clusters and orientation of attached particle clusters in the region of lower drag. The orientation of attached clusters into the region of lower drag reduces backwash efficiency since these clusters are shielded from the hydrodynamic flow. Numerical simulations are applied to identify how the size of clogging formation and the colloidal interaction control the backwash. The results reveal that the particle membrane interaction dominantly controls the backwash efficiency, whereas particle interactions show a lesser impact.

Methodology for hydraulic characterisation of the sand filter backwashing processes used in micro irrigation

The correct operation of the backwashing process in sand filters used in micro irrigation determines directly the effectiveness of the subsequent filtration processes, and consequently the micro irrigation systems maintenance. As backwashing involves the filter bed expansion, the current sand filter design makes it impossible to measure the process. In this sense, this work aims to present a hydraulic characterization methodology of the backwashing process of sand filters used in micro irrigation, evaluating the influence of the sand particle size, the filter bed height, and the sand filter design. The proposed methodology can assist manufacturers in gathering equipment operating information, aiming at its presentation in the product catalogs.•This method article discusses a method of hydraulic evaluation of the backwashing process of sand filters used in micro irrigation.•The method can assist sand filter manufacturers in the correct definition of the equipment's operating parameters.•The method shows the effectiveness of using the filter media pressure loss evaluation in the indirect definition of the minimum fluidisation velocity.

Hysteresis effect on backwashing process in a submerged hollow fiber membrane bioreactor (MBR) applied to membrane fouling mitigation

Hysteresis effect on backwashing in a submerged MBR was investigated with dead-end hollow fiber membranes. The out-of-step changes in TMP and flux is the real hysteresis effect which is common but easily overlooked. Methods of visualization and ultrasonic spectrum analysis were implemented. The results showed that fouling layer is just the culprit of hysteresis effect. Fouling level and fiber length were determined as two key factors that affect hysteresis effect by data and model derivation. Moreover, a hysteresis evaluation index “τbw” is proposed to quantify the result of TMP vs time. The relationship between influence factors and “τbw” is interactive. A linear relationship between fouling level and “τbw” was found as well as an extreme value between fiber length and “τbw”. A lower fouling level (lower backwashing flow) and optimal backwashing duration will be helpful for an effective backwashing no matter for membrane fouling control or energy cost reduce.

Factors influencing backwashing operation in the liquid phase after cake filtration

The separation of solids from process streams takes place in almost every process plant. In particular, cake-forming filtration in the liquid environment is advancing as a widespread method of separating low-concentration suspensions from their solids content and offers energy advantages over other separation principles. In addition to the actual separation performance, the filter fabrics must be regularly replaced or regenerated. The reason for this is the growing resistance because of the increasing filter cake thicknesses. Considering the reduction of disposable products, the regeneration of the fabrics is an interesting possibility to reduce costs and to guarantee a stable process control. This can be achieved by means of filter cake discharge. In the course of this regeneration, the filter cake should be discharged as completely as possible so that the fabric reaches the required initial filtrate flow of the previous filtration cycle again.Investigations concerning cake discharge have shown that the regeneration step can be divided into different discharge mechanisms (complete, partial, resuspended) which result in different cleaning qualities. In the context of this study, backwashing processes with different backwashing parameters (pressure, cake thickness) as well as different particle shapes and their influence on the regeneration quality of filter fabrics are presented and discussed.The focus of this work is the investigation of the backwashing process “cake discharge” as a subsequent and necessary step in cake-forming filtration. Within the scope of this study, a test setup was designed which allows the variation of different process variables and tissue-particle combinations. The experimental setup is kept simple and allows easy reproduction of experiments. The aim is the integrated consideration of the influencing variables on the regeneration quality. The variables cake thickness, particle shape and backwash pressure were investigated within the scope of this study.A significant influence of backwash quality on the examined multifilament filter fabric for particle systems ≤20 µm can be attributed to the particle shape and filter cake thickness. Here, a good regeneration quality can be achieved after exceeding a defined filter cake resistance. This depends significantly on the specific filter cake resistance and thus determines the required cake thickness. Particle systems which, due to their shape and size, have a lower specific cake resistance therefore require a higher cake thickness for a good cleaning result. As a rule of thumb, the absolute filter cake resistance can be estimated with ≥4 ∙ 1010 m−1. A possible influence of the backwash pressure was investigated and can be denied in the range of 0.1–2 bar. The necessary backwash volume in l/m2 was constant over this pressure range. Only the regeneration time decreased, which, relative to the filtration time, is considered insignificant.

Impacts of flow channel geometry, hydrodynamic and membrane properties on osmotic backwash of RO membranes—CFD modeling and simulation

The presence of the spacer and biofilm can accompany the high complexity of the mass and momentum transport in an osmotic backwash (OBW) process of reverse osmosis (RO) membranes. For more reliable simulations, it would be essential to consider such highly complex transport phenomena across the membranes and through membrane flow channels. Therefore, we simulated the effects of spacer designs, hydrodynamic, and membrane properties on OBW in the scenario of biofouling on RO membrane surfaces. To this end, the OBW process was numerically modeled in two-dimensional spacer-filled crossflow channels based on the finite element method. Subsequently, the concentration and velocity fields inside of the membrane, biofilm, and flow channels were analyzed. Results showed that the submerged spacer could enhance the water and salt mass transfer in the membrane channel, to a greater extent than the cavity and zigzag spacers, which can ultimately enhance the OBW efficiency for a foulant removal. Additionally, the OBW performance is chiefly impacted by the structure parameter of the porous support layer. Also, the existence of biofilm in the feed channel can render the feed concentration and membrane water permeability more sensitive to the OBW process than the non-fouled channel.

Bedrock hardness values and morphological zonation of a shore platform in South Africa

Shore platforms found along rock coasts worldwide are often interpreted as wave abrasion acting on uniform bedrock surfaces. Whilst this viewpoint may apply at the macroscale, there are complex feedbacks among bedrock properties (rock type, mineralogy, rock structures), weathering and erosion processes and rates, and microtopography at the meso- to microscale. In turn, these influence wave runup, backwash processes, and the extent of wave-splash and physical, chemical, and biological weathering processes that result. This study investigates the relationships among bedrock hardness properties, microtopography, and shore platform denudation processes from a site on the Indian Ocean-facing coast of South Africa. Three shore-normal transects (45–57 m in length) were surveyed across the sandstone platform using a differential global positioning system (GPS). These data were integrated with rock surface hardness measurements along the transects taken using a Proceq Equotip instrument. Results show that platform morphology and hardness values vary considerably, corresponding to the most dominant denudation processes found at different positions in the tidal frame. The lowest hardness values (most extensive rock weathering) are found on the landward third of the platform but away from the land margin. The highest and greatest variability of hardness values are found on bedrock highs immediately above the highest astronomical tide level, in the lower third of the profile. This position suggests a dominant role of wave-splash and wetting/drying. Variations in hardness values and microtopography through the transects were used to develop an evolutionary model linking rock hardness values to specific weathering and erosion processes of the rocky shore platform.

Optimized design of a novel filter brick in denitrification deep-bed filter.

Denitrification deep-bed filter has been widely applied in the field of advanced wastewater treatment, yet its efficient operation is highly dependent on the filter bricks-controlled water and air distribution system. Considering the restrictions of existing bricks such as poor hydraulic properties and large non-working area during backwashing, a cuboid novel filter brick with two internal distribution chambers was designed and its hydraulic behaviors under three conditions (air washing, water and air joint backwashing, water washing) were simulated using computational fluid dynamic (CFD) analysis. Results showed that the uniformity of fluid velocity distribution was better than that of the conventional brick under two hydraulic conditions, especially in water and air joint backwashing process with a 10% promotion of water and air distribution uniformity. Furthermore, a 30-day engineering validation test was also carried out to testify the actual performance of the novel filter brick. Better performance was testified in the filters with novel bricks. The present study showed that the novel filter brick had a better uniformity of water and air distribution and smaller dead zone area than those of the conventional brick, implying a good feasibility of application in denitrification deep-bed filter.

The Hybrid process of preozonation and CNTs modification on hollow fiber membrane for fouling control

The preozonation and carbon nanotubes (CNTs) modification of hollow fiber membranes for fouling control was systematically evaluated when treating real sewage effluent. The hybrid process was operated in cyclical flow filtration system, involving filtrating and backwashing processes. The results revealed that preozonation and CNTs modification improved fouling control and permeate quality. After preozonation, the fouling rate of the CNTs modified membrane was reduced and its recoverability was effectively improved. With increased ozone dosage, the hybrid effectiveness of preozonation and CNTs modification on fouling control was enhanced. The recoverability of CNTs modified membranes in the hybrid process was improved by increasing the frequency of backwashing. Compared with CNTs’ adsorption effect, the interception effect of CNTs layer pre-deposited during membrane modification increased permeate quality and reduced membrane fouling. The interception effect of CNTs layer was enhanced after preozonation. Confocal laser scanning microscope results demonstrated that the hybrid preozonation and CNTs modification membrane process effectively controlled biofouling. After preozonation, the presence of CNT layers on membrane surfaces could further decrease the amount of living bacteria. The attachment of dead bacteria to CNTs modified membrane was also decreased after preozonation.

Robust Prediction of Filtrate Flux for Separation of Catalyst Particles from Wax Effluent of Fischer-Tropsch Bubble Column Reactor via Regularization Network

Abstract The effectiveness of an internal filtration system intended for separation of wax-catalyst from Fischer–Tropsch synthesis products is investigated in the present study. The generalization performances of in-house Regularization Network (RN) equipped with efficient training algorithm is recruited for prediction of filtrate flux. The network was trained by resorting several sets of experimental data obtained from a specific system of air/paraffin liquid phase/alumina oxide particle conducted in a slurry bubble column reactor. The RN is employed to explore the relationship between the slurry phase temperature (10–60 °C), pressure difference (0.3, 0.6 and 0.9 bar) and time (0–120 min) on the rate of outcome filtrate from various size of filter element (4, 8 and 12 microns). The superior recall and validation performances with different exemplars data points show that the optimally trained RN which has solid roots in multivariate regularization theory, is a reliable tool for prediction of filtrate flux. Faithful generalization performance of RN revels that around 66 % reduction in filtrate flux is observed by decreasing temperature from 60 {}_{}^ \circ C to10 {}_{}^ \circ C for filter pore size of 4 microns. Decreasing of slurry viscosity is the main reason of such behavior. Increasing pressure driving force has a significant effect on elevating filtrate flux. Due to cake formation, filtrate flux is decreased from 2 to 1.4 (ml/min.cm2) at constant temperature of 60 {}_{}^ \circ C for filter pore size of 8 microns. Furthermore, the backwashing process is more effective for smaller pore size filter and temperature variation does not have any considerable effect on filter recovery.

Optimize Backwashing and Filter Ripening Processes

As part of best practices for achieving peak water treatment performance, filtration operation and maintenance are critical. Optimize your facility's backwashing and filter ripening processes for best results.

Membrane Bioreactors Used for Treatment of Food Industry Effluents

Effluents from the food industry determine pollution problems due to high COD and BOD concentrations. Compared to other industrial divisions, food industry requires large amounts of water. In this study, MBR was based on submerged hollow fibers membranes functioning by low vacuum. Two phases of bioreactor treatment were carried out with different HRTs (2-8) and (2-24) hours. Sixteen water samples collected from the influent and the effluent of the bioreactor during the two phases. NaOCl compound was added during the backwashing process for all tests, and the same compound was added with mixed liquid for the second test at period 24 hour of aeration. The samples were tested for twelve water quality tests: temperature, Dissolved Oxygen, pH, Turbidity, Total Suspended Solids, Mixed Liquor Suspended Solids, Chemical Oxygen Demand, Biochemical Oxygen Demand, Nitrate Nitrogen, Ammonium Nitrogen, Total Phosphate, and Ortho Phosphate. The results indicated that the bioreactor system can be used efficiently to treat industrial wastewater from the food industry. The efficiency of the technology was evaluated with sodium hypochlorite addition to removing the adherent bacteria on the surface area of hollow fibers. The results showed that the bioreactor under the conditions of the second phase was excellent in removing Turbidity, TSS, COD, and BOD5 with a removal efficiency 99.96%, 89.52%, 93.56%, and 99.36% respectively, when added 82 ml of NaOCl in the bioreactor tank, and was a good removing of TP, and Ortho-P with removal efficiency 60.76% and 48.95% respectively. Otherwise, a negative effect of NaOCl on both of NO3-N and NH4-N was obtained in term of removal where the minimum removal efficiency was observed when adding 82 ml of NaOCl under the conditions of the second phase.

Effect of biological activated carbon filter depth and backwashing process on transformation of biofilm community

The biological activated carbon (BAC) is a popular advanced water treatment to the provision of safe water supply. A bench–scale device was designed to gain a better insight into microbial diversity and community structure of BAC biofilm by using high–throughput sequencing method. Both samples of BAC biofilm (the first, third and fifth month) and water (inlet water and outlet water of carbon filter, outlet water of backwashing) were analyzed to evaluate the impact of carbon filter depth, running time and backwash process. The results showed that the microbial diversity of biofilm decreased generally with the increase of carbon filter depth and biofilm reached a steady–state at the top layer of BAC after three months’ running. Proteobacteria (71.02%–95.61%) was found to be dominant bacteria both in biofilms and water samples. As one of opportunistic pathogen, the Pseudomonas aeruginosa in the outlet water of device (1.20%) was about eight times higher than that in the inlet water of device (0.16%) at the genus level after five–month operation. To maintain the safety of drinking water, the backwash used in this test could significantly remove Sphingobacteria (from 8.69% to 5.09%, p<0.05) of carbon biofilm. After backwashing, the operational taxonomic units (OTUs) number and the Shannon index decreased significantly (p<0.05) at the bottom of carbon column and we found the Proteobacteria increased by about 10% in all biofilm samples from different filter depth. This study reveals the transformation of BAC biofilm with the impact of running time and backwashing.

Diatomite enhanced dynamic membrane technology for simultaneous backwash sludge pre-dewatering and backwash wastewater recycling

A novel diatomite−enhanced dynamic membrane (DM) technology was investigated for simultaneous backwash sludge pre-dewatering and backwash wastewater recycling from the backwashing process of a biological aerated filter (BAF), which was much cleaner and more sustainable than coagulation or centrifugation process. In this study, the backwash wastewater was mixed with diatomite to enhance the formation of the DM layer, which played a key role in backwash wastewater filtration and sludge pre-dewatering. The entire DM filtration process was operated under gravity−driven mode (200 mm water head). The effluent turbidity was reduced to less than 6 NTU at a diatomite addition concentration of 0.6 g/L and was acceptable for reuse in the backwashing process. The backwash sludge was retained on the DM and pre-dewatered to a water content of 87% with 0.6 g/L diatomite addition; this greatly reduced the sludge volume, saving energy and chemicals in subsequent sludge disposal processes. The sludge water content in sedimentation with PACl/PAM was only reduced to 99.5% and the further centrifugation could achieve sludge water content of 97%. In summary, DM technology shows great potential for backwash sludge pre-dewatering and backwash wastewater reuse, simplifying the sludge dewatering process in BAFs.

Prevention of UF membrane fouling in drinking water treatment by addition of H2O2 during membrane backwashing

Although conventional coagulation pre-treatment can mitigate the fouling of ultrafiltration (UF) membrane when treating raw waters, it is insufficient to restrict the development of irreversible fouling and reversible fouling to a low level. In this paper we demonstrate that the intermittent addition of H2O2 into the membrane tank during backwash events (after coagulation pre-treatment) successfully prevented the development of any significant membrane fouling. Laboratory-scale tests were undertaken using two membrane systems operated in parallel over 60 days, one serving as a reference coagulation-ultrafiltration (CUF) process, and the other receiving the H2O2 (CUF-H2O2), with a decreasing dose in three successive phases: 10, 5 and 2 mg/L. The results showed that the addition of H2O2 (via a separate dosing tube) during a 1 min backwash process (at 30 min intervals) reduced the growth of bacteria in the membrane tank, and the associated concentrations of soluble microbial products (SMP, including protein and polysaccharide). This resulted in a much reduced cake layer, which contained significantly less high MW organic matter (>50%), such as EPS, thereby improving the interaction between particles in the cake layer and/or particles and the membrane surface. There was also less organic matter, of all MW fractions, adsorbed in the membrane pores of the CUF-H2O2 system. The addition of H2O2 in the membrane tank appeared to alter the nature of the organic matter with a conversion of hydrophobic to hydrophilic fractions, which induced less organics adsorption within the hydrophobic PVDF membrane pores, and a reduced bonding ability for particles. There was no physico-chemical evidence of any deterioration of the membrane from exposure to H2O2, which indicates the feasibility of applying this novel method of fouling control for full-scale UF based water treatment processes.