Clean Water Flux Research Articles

Effect of different MoS2 morphologies on the formation and performance of adsorptive-catalytic nanocomposite membranes

This study synthesized three MoS₂ morphologies—nanospheres, nanoplatelets, and nanosheets—under varied conditions and incorporated them into chitosan membranes. TEM confirmed unique morphologies and crystallinity. Clean water flux showed that the nanoplatelet (P-CM) membrane had the highest flux due to higher porosity. The P-CM membrane excelled in removing Mn²⁺ and Zn²⁺ ions, achieving 93.0 ± 0.5% and 90.4 ± 1.5% removal, outperforming membranes with nanospheres (S-CM) and nanosheets (T-CM). Its superior performance is attributed to thicker nanoplatelets forming more water channels. The MoS₂‘s tri-layered structure generated reactive oxygen species (ROS) via H₂O₂ catalysis, contributing to enhanced heavy metal removal. These adsorptive-catalytic membranes combine adsorption with catalytic decomposition of heavy metals, highlighting the work’s novelty and superior performance. The membranes demonstrated excellent flux recovery and reusability (96.0 ± 0.5% for P-CM) after chemical cleaning. The findings emphasize the impact of nanomaterial morphologies on membrane performance in water treatment and environmental remediation.

Biomass-based mixed matrix membrane adsorbers for removal of creatinine in dialysate fluid

Dialysate fluid is a vital component in hemodialysis therapy. Processing and reusing spent dialysate in hemodialysis significantly reduces costs and produces environmentally friendly hemodialysis. In this research, mixed matrix membrane adsorbers (MMMAs), which have the potential to recycle spent dialysate, have been developed. MMMA is composed of cellulose acetate (CA)-based polymers synthesized from cellulose isolated from oil palm empty fruit bunches (OPEFB) and integrated with silica (Si) bio-adsorbent from rice husk ash waste. The membrane was cast using the phase inversion method to form MMMAs CA-Si. The MMMAs CA-Si has a porous structure with evenly distributed silica particles. The pristine CA membranes had swelling and porosity degrees of 38.89 % and 21.23 %, while the MMMAs CA-Si had swelling and porosity degrees of 41.43 % and 27.81 %, respectively. The pristine CA membrane had a clean water flux of 86.86 L/m2h, while the MMMAs CA-Si membrane had a 96.25 L/m2h clean water flux. The MMMAs CA-Si has a tensile strength of 15.89 (Kgf/mm2) and an elongation of 14.01 %. The pristine CA membrane had a creatinine adsorption capacity of 2.8 mg/g, while the CA-Si MMMAs membrane had a maximum adsorption capacity of 9.98 mg/g. The maximum adsorption capacity (qm) is 9.98 mg/g MMMAs, equivalent to 24.95 mg creatinine/g silica in MMMAs and the dissociation constant (Kd) value is 1.91 mg/L. Creatinine can be removed from the dialysate through a continuous flow dialysis process using MMMAs CA-Si with a total removal of 10.48 mg/g or above 66.45 %. Creatinine can also be filtered by cross-flow circulation, and the total creatinine removal is above 81.0 %. MMMAs CA-Si can be an alternative separation medium to remove creatinine in the dialysate.

Cellulose acetate and polycaprolactone based photoactive ultrafiltration membrane: A novel approach with UV-switchable photocatalytic activity

The development of self-cleaning, biodegradable polymer-based membranes with anti-fouling properties has gained significant attention. Herein, a novel ultrafiltration membrane made of cellulose acetate blended with polycaprolactone (PCL) was fabricated using a straightforward, non-solvent-induced phase-separation technique. The optimized membrane showed a high clean water flux of up to 71.3 ± 3.25 L/m2/h. It also displayed high mechanical tensile strength with a Young's Modulus of 41.05 MPa, which can be attributed to PCL. A smooth surface was observed from scanning electron microcopy (SEM) and atomic force microscopy (AFM) analysis. The optimized membrane demonstrated 88.8%, 95.4% and 96.8% rejection for 50 mg/L methyl red, crystal violet and eriochrome black T dyes, respectively, with an average flux of 53.3 ± 1.6 L/m2/h. The optimized membrane was encased and immobilized with 2% TiO2 to demonstrate TiO2-assisted UV-switchable photocatalytic properties, as confirmed by x-ray diffraction (XRD) analysis. The membrane rejected the dyes without UV-LED light and exhibited self-cleaning ability in the presence of UV-LED light (at λmax = 365 nm) and 20 mg/L H2O2 within 2 h. Anti-fouling, self-cleaning biodegradable membranes exhibit potential for sustainable water treatment due to their excellent anti-fouling characteristics from balanced hydrophilic-hydrophobic moieties in the polymeric matrix and the smooth surface.

Synergistic effect of alternating current-based electric and acoustic fields on flux recovery in crossflow microfiltration of synthetic wastewater

The main objective of this study was to investigate the feasibility of synergistic recovery of flux (i.e., 1 + 1 > 2) and fouling mitigation, in the presence of simultaneous application of alternating current (AC)-based electric and acoustic fields during crossflow microfiltration of synthetic wastewaters. We, first, designed a novel crossflow microfiltration apparatus to investigate synergistic effect of AC electric and acoustic fields; secondly, conducted fouling studies on (a) synthetic wastewater alone and (b) synthetic wastewater containing 1.2 × 108 particles/L of silica particles (300 nm SiO2), Micrococcus luteus (500–1000 nm), or a mixture of SiO2 and M. luteus at 50 % each by count, respectively; thirdly, studied the effect of several parameters, including AC electric field strength, acoustic field frequency, foulant type and composition, and pH of synthetic wastewater on fouling; and finally, assessed the significance of synergistic effect of fields on flux recovery using 22 two-level factorial analysis. Results revealed that the application of combined fields recovered 21 % of clean water flux which is significantly higher than those obtained by electric field (4 %) or acoustic field (6 %) alone. The non-linear relationship between flux recovery and each test parameter suggested that the effectiveness of field-assisted membrane processes is determined by multiple competing or mutually enhancing mechanisms − such as electro- and acousto-kinetics, and adsorption and agglomeration of particles − which were proposed to explain the synergistic effect of fields on flux recovery. This study demonstrated the combined AC electric and acoustic fields can synergistically amplify the flux recovery in crossflow microfiltration of synthetic wastewaters.

Valorising Nutrient-Rich Digestate as a Waste-Based Media for Microalgal Cultivation: Bench-Scale Filtration Characterisation and Scale-Up for a Commercial Recovery Process

Cultivating microalgae requires a nitrogen and phosphorous feed source. Anaerobic digestion waste (digestate) provides a cheap sustainable feedstock for these materials. Previous studies have successfully demonstrated the feasibility of nutrient recovery and subsequent algae growth. There is now a need to fully characterise digestate filtration to improve our understanding of this process prior to its commercialisation. In this work, digestate filtration is characterised at bench scale using frontal (dead-end) filtration and a 100 kDa MWCO ultrafiltration membrane. Our experiments demonstrated rapid cake formation causing significant flux decline. The steady-state permeate flux for digestate was 2.4 to 4.8 L m−2 h−1, a reduction of ~90% compared to clean water flux. The specific cake resistance was ~1015 m kg−1 and the compressibility index 1.07. A series of four filtration and cleaning cycles showed 90% flux recovery following a clean water wash. Digestate filtration was then evaluated at a commercial scale using crossflow and the KOCH ABCOR® tubular membrane (100 kDa MWCO). The results were similar to those at the bench scale, i.e., rapid initial fouling leading to a period of steady-state flux (approximately 7 L m−2 h−1). The commercial membrane was flushed with water and diluted bleach after each use, and a digestate permeate flux decline of only 4.8% over a 12-month active use period was observed. The present research provides bench scale characterisation and demonstrates the commercial scale operation of anaerobic digestate filtration using ultrafiltration. The overall filtration performance was excellent, and the process can now be scaled to any operational capacity.

Fabrication of Polyvinylidene Difluoride Membrane with Enhanced Pore and Filtration Properties by Using Tannic Acid as an Additive.

Potential use of tannic acid (TA) as an additive for fabrication of polyvinylidene difluoride (PVDF) membrane was investigated. The TA was introduced by blending into the dope solution with varying concentrations of 0, 1, 1.5, and 2 wt%. The prepared membranes were characterized and evaluated for filtration of humic acid (HA) solution. The stability of the membrane under harsh treatment was also evaluated by one-week exposure to acid and alkaline conditions. The results show that TA loadings enhanced the resulting membrane properties. It increased the bulk porosity, water uptake, and hydrophilicity, which translated into improved clean water flux from 15.4 L/m2.h for the pristine PVDF membrane up to 3.3× for the TA-modified membranes with the 2 wt% TA loading. The flux recovery ratio (FRR) of the TA-modified membranes (FRRs = 78–83%) was higher than the pristine one (FRR = 58.54%), with suitable chemical stability too. The improved antifouling property for the TA-modified membranes was attributed to their enhanced hydrophilicity thanks to improved morphology and residual TA in the membrane matric.

Chitosan-starch cross-linked citric acid as adsorptive hemodialysis membrane

The development and application of membrane methods in the medical field are essential to separate and eliminate toxins and impurities in the bloodstream through the process of hemodialysis. To be able to eliminate all toxic substances in the body fluid, the hemodialysis membrane must have the dual ability of adsorption properties and diffusion through the pore membrane. The chitosan-starch hemodialysis membrane un-crosslinked and cross-linked has been made to separate creatinine compounds with those with the dual ability to combine diffusion and adsorption from the membrane. Chitosan-binding starch membranes are made using citric acid as a cross-linking agent. Chitosan starch membrane uncross-linked has a clean water flux of 96 Lh−1 m−2, whereas chitosan-starch membrane cross-linked has 90 L h−1 m−2 clean water flux. Chitosan-starch membrane uncross-linked can remove creatinine of 11.89 mg/gram where the amount removed by adsorption reaches 8.66 mg/gram membrane. The chitosan-starch cross-linked membrane can remove creatinine 9.86 mg/gram membrane with the amount removed by adsorption reaching 5.14 mg/gram membrane. Chitosan-starch membranes have hemodialysis characteristics that are integrated with adsorption, where blood toxins are released in one step.

Improvement of Properties and Performances of Polyethersulfone Ultrafiltration Membrane by Blending with Bio-Based Dragonbloodin Resin.

Polyethersulfone (PES) is the most commonly used polymer for membrane ultrafiltration because of its superior properties. However, it is hydrophobic, as such susceptible to fouling and low permeation rate. This study proposes a novel bio-based additive of dragonbloodin resin (DBR) for improving the properties and performance of PES-based membranes. Four flat sheet membranes were prepared by varying the concentration of DBR (0–3%) in the dope solutions using the phase inversion method. After fabrication, the membranes were thoroughly characterized and were tested for filtration of humic acid solution to investigate the effect of DBR loading. Results showed that the hydrophilicity, porosity, and water uptake increased along with the DBR loadings. The presence of DBR in the dope solution fastened the phase inversion, leading to a more porous microstructure, resulted in membranes with higher number and larger pore sizes. Those properties led to more superior hydraulic performances. The PES membranes loaded with DBR reached a clean water flux of 246.79 L/(m2·h), 25-folds higher than the pristine PES membrane at a loading of 3%. The flux of humic acid solution reached 154.5 ± 6.6 L/(m2·h), 30-folds higher than the pristine PES membrane with a slight decrease in rejection (71% vs. 60%). Moreover, DBR loaded membranes (2% and 3%) showed an almost complete flux recovery ratio over five cleaning cycles, demonstrating their excellent antifouling property. The hydraulic performance could possibly be enhanced by leaching the entrapped DBR to create more voids and pores for water permeation.

Manufacture of Layered-type MF Ceramic Membrane for Advanced Wastewater Treatment and its Fouling Control using Modularized Mechanical Scraper

In this study, a novel layered-type microfiltration (MF) ceramic membrane for advanced wastewater treatment was fabricated; composed of the support, buffer layer, and active layer. The buffer and active layers allow for the easy formation of the active layer on the support and selective permeation of the ceramic membrane, respectively. The average pore sizes of the support, buffer layer, and active layer were 2,677, 773.3, and 33.1 nm, respectively. The diameters of the active layer pores were <0.1 μm. The ceramic membrane performance and mechanical scraping effects on the membrane permeability improvement were evaluated. Mixed liquor suspended solids (MLSS) were used for the feed of an enhanced ceramic membrane filtration system, by combining the fabricated membranes and devised scrapers. The average flux recovery by scraping was 54% of the clean water flux; maintained by scraping despite the high turbidity feed. The permeation concluded within 0.2 h during scrape-off. This was not recovered despite scraping because the internal membrane pores became blocked due to the material turbidity and could not be separated at the surface of the ceramic membrane.

Modification of PVDF hydrophobic microfiltration membrane with a layer of electrospun fibers of PVP-co-PMMA: Increased fouling resistance

A wide range of materials can be used for membrane production for wastewater treatment using membrane technology. Polymeric membranes have the disadvantage of high fouling tendency when used for oil-water wastewater, reducing the membrane flux. In this study, a simple superficial modification with polydopamine (PDA) coating was used, combined with the electrospinning technique to create an additional layer over the hydrophobic commercial polyvinylidene fluoride (PVDF) membrane, to achieve a hydrophilic surface and fouling resistance for oil-water separation. PVDF microfiltration membrane, with 0.22 μm of pore size, was modified with PDA by deposition for 12 h. A layer of polyvinylpyrrolidone-co-polymethyl methacrylate (PVP-co-PMMA) was electrospun over the modified polydopamine membrane. The modified membrane showed a hydrophilic surface, with a higher clean water flux and a reduction of fouling during emulsion filtration, when compared with the commercial microfiltration PVDF membrane. So that a simple modification, forming a multilayer membrane, increased up to 4 times of clean water flux after the cleaning procedure of the membrane.

Analysing organic micropollutant accumulation in closed loop FO–RO systems: A pilot plant study

Long-term operation of a forward osmosis – reverse osmosis (FO–RO) closed loop pilot plant is presented. The system was fed with a single batch of clean tap water into which organic micropollutants were spiked; RO permeate was recirculated to the FO feed. The system was operated in two different runs, with NaCl and MgCl2 as draw solutes. Over the course of the pilot plant trials, the organic micropollutants migrated into the draw solution closed-loop, reaching an equilibrium with the FO feed. This implies that there was strong accumulation of the organic micropollutants in the draw solution, up to a factor of 50 relative to the FO feed. FO rejection was variable between 55 and 91% for the different micropollutants, while RO rejection was high in all cases: in excess of 99% for all but one organic micropollutant. The extent of micropollutant accumulation in the draw solution was related to high RO selectivity and internal concentration polarization within the FO membrane’s support layer. In turn, FO permeability and the extent of accumulation were found to correlate negatively: well-rejected compounds accumulated slower in the draw solution loop, but to a higher extent. The FO membrane’s structural parameter, as obtained from clean water flux tests using mineral salt draw solutes, was a poor predictor of organic micropollutant internal concentration polarization.

Separation of COD, sulphate and chloride from pharmaceutical wastewater using membrane integrated system: Transport modeling towards scale-up

• Nanofiltration applied to reclaim water from complex pharmaceutical wastewater. • Coupled mathematical model was followed to develop the transport model. • The model successfully validated performance of flat-sheet membranes in cross-flow modules. • The model demonstrated almost complete pollutant removal with high clean water permeation. • Developed semi-pilot system through scale-up confirms clean water production at 0.89 $/m 3 . The effluent from the pharmaceutical industries is a serious threat to the environment because of the existence of high chemical oxygen demand, ionic Chloride and Sulphate concentrations. To bring down the pollutant level as per environmental safe discharge regulations, a nanofiltration based semi pilot based system is proposed to recover clean water in continuous mode from pharmaceutical effluent. The experimental results were validated by the newly developed mathematical model, used for the transportation of molecules through nanofiltration membrane. Such mathematical approach was constructed on the basis of Extended Nernst–Planck equation which was further linearized and applied for the simulation. Effects of governing parameters like operating pressure, feed flow rates across membrane surface, constituents of feed solutions, solution pH and operational time on membrane solute rejection and solvent flux were analysed. It was found that the model predicted results corroborated extremely well with the experimental results with less relative error (<0.09), high regression (R 2 >99 %) and Willmott-d-index (>98 %), generating a steady state clean water flux of 110 L/m 2 h at 12 bar operating pressure and at a cross flow rate of 750 L/h with more than 98 % rejection to active pharmaceutical ingredients, chemical oxygen demand and other toxic molecules. Economic assessment with Scale-up shows that the proposed system is promising in producing clean water at a low cost (US 0.89 $/m 3 ) by purifying pharmaceutical wastewater.

Garlic-based phenolic nanopowder as antibiofouling agent in mixed-matrix membrane

The mixed matrix membrane has been developed in this work by using cellulose acetate as a membrane matrix and garlic-based phenolic nanopowder as an anti-biofouling filler. The membrane prepared using the phase inversion method, utilizing dimethylformamide (DMF) as a solvent. Three variation of garlic extract (GE) nanopowder concentration of 0.5%, 0.75%, and 1% were used, respectively. The mixed matrix membranes were tested their final thickness, morphology by using SEM, tensile strength, elasticity, clean water flux, and bacterial adhesion. Anti-biofouling activities of the garlic extract nanopowders were confirmed from the Escherichia coli bacterial adhesion, which 32 cells adhered in the pristine membrane surface, whereas nanopowder concentration of 0.5%, 0.75%, and 1% mixed matrix membranes show 9, 12 and 10 cells adhered in the membrane surface, respectively. The phenolic compounds in the mixed matrix membranes were able to inhibit bacterial growth and potentially used for a safe and non-toxic tool for food processing, including juice clarification.

Kaplanmış Seramik Membranla Rekabetli Ağır Metal Adsorpsiyonu ve Rejenerasyon Yöntemlerinin İncelenmesi

In this study, active surface of ceramic membrane was modified with silica layer and amino groups in order to improve the treatability of industrial wastewater with heavy metal content. As the separation capabilities of the developed membrane increased, it became more selective for metal ions in industrial wastewaters. The modified membrane is characterized by SEM-EDX, membrane surface charge, and XRF measurements. The affinities and rejection capacities of heavy metals in industrial wastewater on the coated ceramic membrane were investigated at constant concentration and pressure (6.5 mg / L, 2 bar) with single, triple and 5-mixture model solutions. Then, 2 different regeneration methods were applied to the coated ceramic membrane. To determine the regeneration capacity of coated ceramic membrane with optimum regeneration method; 3 different pressures (1,2 and 4 bar) and 3 different concentrations (6,5, 64 and 128 mg / L) of copper containing model solution and industrial wastewater were tested and compared with the clean water flux after regeneration. In single experiments the removal order was obtained as Cu2+>Pb2+>Ni2+>Zn2+>Fe2+. In triple tests removal order of Pb2+>Ni2+>Cu2+ and Zn2+>Cu2+>Fe2+ was obtained. In the removal test where all metals are combined, the result was obtained as Pb2+>Ni2+>Zn2+>Cu2+>Fe2+ which is similar to the results of the studies in the literature. As a result of the tests performed, coated ceramic membranes were able to recover their initial performance after regeneration. ICP-MS analysis of the samples taken from the regeneration stream after coated membrane experiments 26,84-33,73 mg/L copper was found. By the multi-channel ceramic membrane tests which will be conducted in future studies, it is expected that the coating will strengthen the adsorption process by covering a larger surface area on ceramic membranes and reduce the process costs with obtained higher fluxes.

Experimental study of the flux Law of flat ceramic membranes under different pressures

Abstract The flux performance of ceramic membranes is the basis for their efficient use. To study ceramic membrane flux variation, different filtration operating conditions were tested and the functional relationship between the membrane's clean water flux and the operating pressure within a given range obtained. The membrane's critical pressure and flux were determined by using pressure increments, and the flux variation law under different pressures determined experimentally. Analysis of the flux law and the membrane parameters enabled establishment of the flux model of filtration process and a model of flux stabilization after the deposition layer formed. The applicability of the model was proved by comparing and verifying the experimental data.

Recycling of coal fly ash for fabrication of elongated mullite rod bonded porous SiC ceramic membrane and its application in filtration

Mullite bonded SiC ceramic membranes were synthesized by a facile solid-state reaction process, using SiC, solid waste fly ash as raw materials and MoO3 as catalyst for growth of mullite at 1000 °C. The effect of MoO3 catalyst on mullitization reaction and mullite morphology was investigated. Different pore formers were used to enhance the porosity and to observe its effects on the permeability parameters and filtration characteristics. At room temperature Darcian (k1) and non-Darcian (k2) in both water and air flow were measured and clean water flux was determined. The porous SiC ceramics with addition of 5 wt.% MoO3 exhibited a flexural strength of 38.4 MPa at porosity 36.4 vol% and showed 92% oil removal efficiency from oily wastewater. This technique, combining low-cost materials and the co-sintering at low temperature, can serve as a cost-effective method for the production of high-performance porous SiC ceramic membrnaes for filtration application.

Drinking Water Bags Based on Chitosan Forward Osmosis Membranes for Emergency Drinking Water Supply

A fast and simple method and technologies in drinking water supply are strongly needed in an emergency situation. One alternative method is based on membrane forwards osmosis (FO) technology. In this study, chitosan-based FO membranes have been developed into drinking water bags used as purification media for dirty water and seawater. The chitosan membrane used for the assembly of drinking water bags has a thickness of 0.043 mm, the porosity of 30.3%, the tensile strength of 28.83 kgf / mm2, swelling degree of 43.5% and elongation of 7.16%. The drinking water bags are made from a combination of polypropylene plastic (PP) and aluminum foil plastic with the interface of the FO membrane inside. The drinking water bag can be applied to purify dirty water and seawater into energy drinking water, which can be used for drinking water supply in an emergency situation. Energy drinks water is produced from the FO process using a variety of draw solution, specifically glucose, fructose, and sucrose. The highest drinking water flux was obtained by using 3M sucrose concentration as a draw solution. The clean water fluxes for dirty water and seawater samples were 5.25 L/m2hour and 4.25 L/m2hour respectively. The parameters drinking water quality test are proved that pH, total dissolved solids (TDS), salinity, electrical conductivity, heavy metals and the content of Escherichia coli bacteria are agreed with drinking water quality standards based on PERMENKES regulations No. 492/MENKES/Per/IV/2010. The FO drinking water bag based chitosan membrane has the potential to be used as an alternative solution for energy drinking water supply in an emergency.

Influences of nano zero valent ion and Fe2+ supported kaolin nanoparticles for metal ion separation thorough ultrafiltration

In this work, clay based nanocomposite material was synthesized by wet chemical route and nano zero valent ion of kaolin (nZVI:Kaolin) were prepared using sodium borohydride reduction method. The nZVI:Kaolin and Fe:Kaolin nanoparticles were characterized using XRD, FTIR and SEM and antimicrobial activity. The nZVI:Kaolin and Fe:Kaolin were incorporated into polyethersulfone (PES) membranes for metal ion separation through ultrafiltration. The influences of nZVI:Kaolin and Fe supported clay nanoparticles on PES membranes were characterized their modification in functional properties, hydrophilicity and morphological structure. The clean water flux was enhanced to PES membrane by addition of nZVI:Kaolin and Fe:Kaolin nanoparticles. The Cu (ii), Ni (ii) and Cd (ii) metal ions flux was increased for 0.15 wt% of nZVI and Fe:Kaolin nanoparticles in PES which is due to increase in hydrophilicity and change in morphological structure.

Enhanced antibiofouling properties of chitosan-based membranes by coating and blending of Moringa Oleifera L extracts

During application of ultrafiltration membrane for fruit juice clarification, biofouling occurred as the process deals with food substances. Chitosan-based membrane has potential to reduce membrane biofouling, however the performance is still requiring improvement. Natural antibiotics such as Moringa oleifera leaves and nuts extracts might be used to improve the antibiofouling properties of ultrafiltration membrane. We investigated the method to adhere Moringa oleifera extracts into chitosan-based ultrafiltration membranes. Two methods were investigated, i.e. coating and blending. The modified membranes were then immersed in Escherichia coli solution to test the anti-biofouling effect, alongside clean water flux test. The results show that by increasing Moringa oleifera extract concentration from 0%, 2.5% and 5% by using coating method, the mean clean water fluxes are similar in ± 5000-6000 L/m2h, while blending method provide less clean water fluxes, i.e. ± 6.000 L/m2h, 2.150 L/m2h, 4.462 L/m2h, for blending Moringa oleifera extract concentration from 0%, 2,5% and 5%, respectively. The lower clean water flux for blending method is due to smaller pore sizes of chitosan membrane which was filled by Moringa oleifera extract. With regards to bacteria adhesion, by observing 200μm membrane area under microscope, and analyzing the images, the total area of Escherichia coli attachment onto membrane surface are 38.07%, 4.57%, 0.57% for coating Moringa oleifera extract concentration of 0%, 2,5% and 5%, respectively. This result is better than blending methods that promotes 38.7%, 11.22% and 32.87% total area of Escherichia coli attachment onto membrane surface, by increasing blending concentration of 0%, 2,5% and 5%, respectively.

Congo red dye removal by direct membrane distillation using PVDF/PTFE membrane

The ability to use the membrane distillation (MD) technique is envisaged as a promising approach to attain sustainable and reliable clean water supply. In this work, polytetrafluoroethylene/polyvinylidene fluoride (PVDF/PTFE) flat sheet membranes were fabricated via the thermally induced solvent evaporation process. The PVDF/PTFE membrane surface was modified by incorporating methyl functionalized mesoporous silica nanoparticles (MfSNPs). Prior to application, the membranes were characterized with respect to surface and structural morphology, hydrophobicity and overall porosity. Clean water flux measurements were conducted using a direct contact membrane distillation (DCMD) lab-scale experimental setup with deionized water as the feed solution (50 °C) and permeate solution (20 °C). The highest stable pure water flux for the MfSNPS/PVDF/PTFE membranes was 0.0041 L/h m2. The incorporation of the MfNPS did not only improve the fluxes but also induced low wetting properties as shown by the contact angle and LEPw values. The MfSNPs/PVDF/PTFE membranes were highly efficient in removing Congo red dye from water with 99% removal efficiency achieved.