Pressure-driven Membrane Technologies Research Articles

Removal of Heavy Metals from Wastewaters and Other Aqueous Streams by Pressure-Driven Membrane Technologies: An Outlook on Reverse Osmosis, Nanofiltration, Ultrafiltration and Microfiltration Potential from a Bibliometric Analysis.

A bibliometric study to analyze the scientific documents released until 2024 in the database Scopus related to the use of pressure-driven membrane technologies (microfiltration, ultrafiltration, nanofiltration and reverse osmosis) for heavy metal removal was conducted. The work aimed to assess the primary quantitative attributes of the research in this field during the specified period. A total of 2205 documents were identified, and the corresponding analysis indicated an exponential growth in the number of publications over time. The contribution of the three most productive countries (China, India and USA) accounts for more than 47.1% of the total number of publications, with Chinese institutions appearing as the most productive ones. Environmental Science was the most frequent knowledge category (51.9% contribution), followed by Chemistry and Chemical Engineering. The relative frequency of the keywords and a complete bibliometric network analysis allowed the conclusion that the low-pressure technologies (microfiltration and ultrafiltration) have been more deeply investigated than the high-pressure technologies (nanofiltration and reverse osmosis). Although porous low-pressure membranes are not adequate for the removal of dissolved heavy metals in ionic forms, the incorporation of embedded adsorbents within the membrane structure and the use of auxiliary chemicals to form metallic complexes or micelles that can be retained by this type of membrane are promising approaches. High-pressure membranes can achieve rejection percentages above 90% (99% in the case of reverse osmosis), but they imply lower permeate productivity and higher costs due to the required pressure gradients.

Perfluorooctanoic acid-contaminated wastewater treatment by forward osmosis: Performance analysis

Perfluorooctanoic acid (PFOA) is a persistent compound, raising considerable global apprehension due to its resistance to breakdown and detrimental impacts on human health and aquatic environments. Pressure-driven membrane technologies treating PFAS-contaminated water are expensive and prone to fouling. This study presented a parametric investigation of the effectiveness of cellulose triacetate membrane in the forward osmosis (FO) membrane for removing PFOA from an aqueous solution. The study examined the influence of membrane orientation modes, feed pH, draw solution composition and concentration, and PFOA concentration on the performance of FO. The experimental results demonstrated that PFOA rejection was 99 % with MgCl2 and slightly >98 % with NaCl draw solutions due to the mechanism of PFOA binding to the membrane surface through Mg2+ ions. This finding highlights the crucial role of the draw solution's composition in PFOA treatment. Laboratory results revealed that membrane rejection of PFOA was 99 % at neutral and acidic pH levels but decreased to 95 % in an alkaline solution at pH 9. The decrease in membrane rejection is attributed to the dissociation of the membrane's functional groups, consequently causing pore swelling. The results were confirmed by calculating the average pore radius of the CTA membrane, which increased from 27.94 nm at pH 5 to 30.70 nm at pH 9. Also, variations in the PFOA concentration from 5 to 100 mg/L did not significantly impact the membrane rejection, indicating the process's capability to handle a wide range of PFOA concentrations. When seawater was the draw solution, the FO membrane rejected 99 % of PFOA concentrations ranging from 5 mg/L to 100 mg/L. The CTA FO treating PFOA-contaminated wastewater from soil remediation achieved a 90 % recovery rate and water flux recovery of 96.5 % after cleaning with DI water at 40 °C, followed by osmotic backwash. The results suggest the potential of using abundant and cost-effective natural solutions in the FO process, all without evident membrane fouling.

Landfill Leachate Treatment by Using Second-Hand Reverse Osmosis Membranes: Long-Term Case Study in a Full-Scale Operating Facility.

Landfill leachate (LFL) has a complex inorganic, organic and microbiological composition. Although pressure-driven membrane technology contributes to reaching the discharge limits, the need for frequent membrane replacement (typically every 1-3 years) is an economical and environmental limitation. The goal of this work is to evaluate the feasibility of using second-hand reverse osmosis (RO) membranes to treat LFL in an industrially relevant environment. End-of-life RO membranes discarded from a seawater desalination plant were first tested with brackish water and directly reused or regenerated to fit with requirements for LFL treatment. A laboratory scale test of second-hand membrane reuse was carried out using ultrafiltered LFL. Then, a long-term test in an LFL full-scale facility was performed, where half of the membranes of the facility were replaced. The industrial plant was operated for 27 months with second-hand membranes. The permeate water quality fit the required standards and the process showed a trend of lower energy requirement (up to 12 bar lower transmembrane pressure and up to 9% higher recovery than the average of the previous 4 years). Direct reuse and membrane regeneration were successfully proven to be an alternative management to landfill disposal, boosting membranes towards the circular economy.

Технологический прорыв аграрно-пищевых инноваций молочного дела на примере универсального сельхозсырья. Электродиализ

Aim. Consideration of the process of pressure driven membrane technology such as electrodialysis – targeted and operable whey and whey permeate treatment with an aim of demineralization and ash concentration reduction. Electrodialysis use in dairy industry all over the world (as well as in Russia) and allows implementing technological breakthrough in the area of widespread whey application for food and feed supplements of new generation. Discussion. Native whey electrodialysis is a separate branch of pressure-driven membrane technology of molecular-sieve separation which usually applied after defatting, casein clusters separation and also intended for whey permeates (UF, NF, MF, DF) treatment. NF-retentates demineralization is an inherent part of raw materials preparation for supersaturated syrups crystallization and spray drying in production line of food and pharmaceutical lactose. Conclusion. In general, production of dry demineralized whey and its permeates is practically impossible without demineralization by a method of electrodialysis due to high ash concentration.

Pressure-Driven Membrane Process: A Review of Advanced Technique for Heavy Metals Remediation

Pressure-driven processes have come a long way since they were introduced. These processes, namely Ultra-Filtration (UF), Nano-Filtration (NF), and Reverse-Osmosis (RO), aim to enhance the efficiency of wastewater treatment, thereby aiming at a cleaner production. Membranes may be polymeric, ceramic, metallic, or organo-mineral, and the filtration techniques differ in pore size from dense to porous membrane. The applied pressure varies according to the method used. These are being utilized in many exciting applications in, for example, the food industry, the pharmaceutical industry, and wastewater treatment. This paper attempts to comprehensively review the principle behind the different pressure-driven membrane technologies and their use in the removal of heavy metals from wastewater. The transport mechanism has been elaborated, which helps in the predictive modeling of the membrane system. Fouling of the membrane is perhaps the only barrier to the emergence of membrane technology and its full acceptance. However, with the use of innovative techniques of fabrication, this can be overcome. This review is concluded with perspective recommendations that can be incorporated by researchers worldwide as a new problem statement for their work.

Membrane technologies in toilet urine treatment for toilet urine resource utilization: a review.

Membrane technologies have broad potential in methods for separating, collecting, storing, and utilizing urine collected from toilets. Recovering urine from toilets for resource utilization instead of treating it in a sewage treatment plant not only reduces extra energy consumption for the degradation of N and P but also saves energy in chemical fertilizer production, which will contribute to carbon emission reduction of 12.19–17.82 kg kgN−1 in terms of N alone. Due to its high efficiency in terms of volume reduction, water recycling, nutrient recovery, and pollutant removal, membrane technology is a promising technology for resource utilization from urine collected from toilets. In this review, we divide membrane technologies for resource utilization from urine collected from toilets into four categories based on the driving force: external pressure-driven membrane technology, vapor pressure-driven membrane technology, chemical potential-driven membrane technology, and electric field-driven membrane technology. These technologies influence factors such as: recovery targets and mechanisms, reaction condition optimization, and process efficiency, and these are all discussed in this review. Finally, a toilet with source-separation is suggested. In the future, membrane technology research should focus on the practical application of source-separation toilets, membrane fouling prevention, and energy consumption evaluation. This review may provide theoretical support for the resource utilization of urine collected from toilets that is based on membrane technology.

Hybrid sorption and pressure-driven membrane technologies for organic micropollutants removal in advanced water reclamation: A techno-economic assessment

The persistence of certain organic-micropollutants (OMP) in conventional wastewater and reclamation treatments represents a growing concern due to its associated uncertain effects on human health and the environment. This issue highlights the need to resort to advanced treatment technologies to ensure the maximum removal of these compounds. A prototype (1.5–2 m3/h) based on the combination of powdered activated carbon (PAC) with tight ultrafiltration (UF) membranes was operated in El Baix Llobregat Water Reclamation Plant (WRP) for 18 months. Its performance was compared from a technical and economic point of view with the current full-scale ultrafiltration and reverse osmosis system (UF-RO with 50% blend). The application of a PAC concentration of 20 mg/L and its separation with UF membrane resulted in an average removal up to 81 ± 13% of the most recalcitrant OMP detected (Carbamazepine (CBZ), Diuron (DIU), Diclofenac (DCF), Erythromycin (ERY) and Sulphametoxazole (SMX)), while in UF-RO (50% blend), the average removal was 55 ± 11%. PAC-tight UF presented promising advantages for when these post-treatments need to be implemented in inland WRP and where brine management can represent a drawback. Moreover, PAC-tight UF presents 22% higher Operational Expenditures (OPEX) than UF-RO (50% blend), although in terms of Capital Expenditure (CAPEX), it appears as the less expensive option.

Functionalized imidazolium ionic liquids promote seawater desalination through forward osmosis

Carboxylate-functionalized imidazolium ionic liquids (CFIMILs) were synthesized via a one-pot quaternization reaction and serve as draw solutes for the first time for forward osmosis (FO) desalination. It provides a solution to simultaneously overcome the problems plaguing the use of pressure-driven membrane technologies to extract water from saline water – low water recovery efficiency and high reverse solute diffusion. The CFIMILs contain a substituted 5-membered imidazole ring and fully ionize into ionic species in water. These characteristics endow CFIMILs with capability of high water recovery efficiency and minimal reverse diffusion in FO. Sodium salt of 1-acetate-2,3-dimethyl imidazole ionic liquid (IL-1) at 0.8 M produces water fluxes of 63.6 LMH (PRO mode) and 29.5 LMH (FO mode) against the DI water feed, greatly outperforming conventional NaCl draw solute and other synthetic draw solutes. Efficient water recovery is achieved using IL-1 for seawater desalination with a water flux 5 times higher than that of NaCl. Particularly, CFIMILs draw solutes have negligible reverse diffusion in FO and are recycled completely via an MD process with good reproducibility when reused to FO, demonstrating great potentials of CFIMILs as a new class of draw solutes for FO water treatment.

Pressure-driven membrane processes involved in waste management in agro-food industries: A viewpoint

To date, according to the latest literature inputs, pressure-driven membrane technologies (i.e. microfiltration, ultrafiltration and nanofiltration) are a latent alternative for the integral management of agro-food by-products, which are commonly produced in food processing industries. Primarily, these membrane technologies were proposed for the treatment of wastes. Nowadays, based on the current tendencies of the circular economy, which deals with the reuse of such wastes, the role of the membrane technology has shifted to the valorization of the agro-industrial by-products. Thereby, this short communication provides an outlook on the utilization of aqueous wastes from industries, highlighting the real advantages that these methodologies offer in terms of high-added value solute recovery. Moreover, the environmental benefits of membrane technology (water reclamation) are also given.

Shear stress in a pressure-driven membrane system and its impact on membrane fouling from a hydrodynamic condition perspective: a review

Pressure-driven membrane technology has gained increasing popularity in municipal/domestic and industrial wastewater treatment, desalination, and water reclamation. Careful manipulation of surface shear stress, which plays a vital role in membrane fouling control from a purely hydrodynamic perspective, can minimise concentration polarisation of solute on flat sheet membranes, or enhance the particle back transport from hollow fibre membranes. This review considers the techniques to generate turbulence and shear at the membrane surface, the magnitude of shear stress, and the experimental, as well as numerical methods for evaluation of shear stress. The findings are presented in terms of the amount of shear stress reported to control membrane fouling in these systems. Operational disadvantages of fouling control via application of shear stress occur while changing the properties of the solute or particles, such as cell breakup, bacterial population change, or shear stress classification. The literature teaches that future developments on shear stress for membrane systems must be addressed, in addition to energy consumption, shear stress distribution and the development of combined analytical methods to characterise and visualise shear in situ for different membrane configurations. © 2016 Society of Chemical Industry

INCORPORATION OF BACTERICIDAL NANOMATERIALS IN DEVELOPMENT OF ANTIBACTERIAL MEMBRANE FOR BIOFOULING MITIGATION: A MINI REVIEW

Biofouling has become concern issue in all pressure driven membrane technology. The attachment of microorganism to the membrane surface gave an effect to membrane life span, increased operating and maintenance costs. Therefore, this review is focusing on the development of nanocomposite membrane based on improving bactericidal properties to suppress the activity of attached organisms in order to minimize biofilm formation. This approach was done with incorporation of biocidal nanomaterials into a polymeric membrane matrix by include metal-based nanoparticles such as Titanium dioxide (TiO2), Copper (Cu), Silver (Ag), Zinc oxide (ZnO); carbon-based nanomaterials including graphene oxide (GO) and carbon nanotubes (CNTs) and hybrid nanomaterials. Current constraints and prospective by the use of nanomaterials are discussed in order to increase antibacterial property for long term application for further implementation in membrane systems from the views of water and wastewater treatment applications.

Physicochemical analysis and adequation of olive oil mill wastewater after advanced oxidation process for reclamation by pressure-driven membrane technology

Physicochemical characterization of olive mill wastewaters (OMW) was studied after a primary and secondary treatment was implemented in an olive oil factory in Jaén (Spain), comprising natural precipitation, Fenton-like reaction, flocculation–sedimentation and olive stone filtration in series. The application of membrane technology in improving the quality of the secondary-treated OMW (OMW/ST) was examined, to reduce the hazardous electroconductivity (EC) values (2–3mScm−1). Particle size distribution on OMW/ST shows supra-micron colloids and suspended solids as well as sub-micron particles with a mean size below 1.5μm remaining in considerable concentration. The high organic pollutants percentage (31.7%) registered with an average diameter below 3kDa is sensibly relevant for membrane fouling. Mesophilic aerobic bacteria growth warns of possible membrane biofouling formation. The saturation index indicates to work upon recovery factor below 90%. Finally, operating at a pressure equal to 15bar ensured low fouling and high flux production on the selected NF membrane (69.9Lh−1m−2) and significant rejection efficiencies (55.5% and 88.5% for EC and COD). This permits obtaining an effluent with good quality according to the recommendations of the Food and Agricultural Association (FAO) with the goal of reusing the regenerated water for irrigation.

The role of membrane technologies in water reuse applications

The world is not running out of water; the relatively fixed quantity is becoming too contaminated for many applications. In many cases, it is possible to collect and treat this contaminated water and reuse it. The crossflow, pressure-driven membrane technologies of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis play an important role in water reuse activities. This study identifies the sources of “used” water (residential, commercial, industrial, and municipal), defines the contaminant parameters, addresses the appropriate membrane treatment technologies, and details system designs necessary to produce water for specific applications, such as potable.

A focus on pressure-driven membrane technology in olive mill wastewater reclamation: state of the art

Direct disposal of the heavily polluted effluent from olive oil industry (olive mill wastewater, OMW) to the environment or to domestic wastewater treatment plants is actually prohibited in most countries, and conventional treatments are ineffective. Membranes are currently one of the most versatile technologies for environmental quality control. Notwithstanding, studies on OMW reclamation by membranes are still scarce, and fouling inhibition and prediction to improve large-scale membrane performance still remain unresolved. Consequently, adequately targeted pretreatment for the specific binomium membrane-feed, as well as optimized operating conditions for the proper membranes, is today's challenge to ensure threshold flux values. Several membrane materials, configurations and pore sizes have been elucidated, and also different pretreatments including sedimentation, centrifugation, biosorption, sieving, filtration and microfiltration, various types of flocculation as well as advance oxidation processes have been applied so far. Recovery of potential-value compounds, such as a variety of polyphenols highlighting oleuropein and hydroxytyrosol, has been attempted too. All this research should constitute the starting point to proceed with OMW purification beyond recycling for irrigation or depuration for sewer discharge, with the aim of complying with standards to reuse the effluent in the olive oil production process, together with cost-effective recovery of added-value compounds.

Performance evaluation of sucrose concentration using forward osmosis

Concentrating sugar solutions is a common process used in the production of many food products for either dewatering a high value product or concentrating waste streams prior to disposal. Thermal and pressure-driven dewatering methods are widely used, but they are prohibitively energy intensive and hence, expensive. Osmotically driven membrane processes, like forward osmosis, may be a viable and sustainable alternative to these current technologies. Using NaCl as a surrogate draw solution, this investigation shows that forward osmosis processes can lead to sucrose concentration factors that far exceed current pressure-driven membrane technologies, such as reverse osmosis. For instance, a concentration factor of 5.7 was achieved by forward osmosis with a starting sucrose concentration of 0.29 M, compared to reported concentration factors of up to 2.5 with reverse osmosis. Water fluxes were found to be lower than those commonly obtained in reverse osmosis, which is a consequence of the significantly higher concentration factors in conjunction with internal concentration polarization. The latter is a common problem in forward osmosis processes that utilize current generation anisotropic polymeric membranes. Further advances in forward osmosis membrane technology would yield higher water fluxes and concentration factors.

Development of membrane technology in BARC

BARC has been engaged in research and development work on pressure-driven membrane technology from laboratory to pilot plant scale and its commercial scale deployment, for sea and brackish water desalination into potable water, effluent water treatment and water reuse and in various industrial separations including docontamination of radioactive liquid effluents for their safe disposal into the environment. This paper gives a brief description of pressure-driven membrane processes, reverse osmosis, nanofiltration, ultrafiltration and microfiltration. Selection of polymeric candidate materials, preparation of semi-permeable membranes and their characterization has been discussed. Various applications of these processes conducted on pilot plant scale have been presented. Large scale deployment of membrane processes for sea water desalination has been indicated. Research and development at BARC has thus resulted in the indigenous development of membrane processes for commercial scale operation.

The Influence of Multiple Fouling and Cleaning Cycles upon the Membrane Processing of Lignosulphonates

Although the application of pressure-driven membrane technology continues to grow, fouling remains a major unsolved problem. Despite the success achieved with mechanical cleaning methods such as backfluushing and backshocking, chemical cleaning-in-place remains the major way to tackle fouling 1–3 . This paper investigates the relationship between fouling and cleaning processes, and how they influence each other over a number of operational cycles. Results are reported for the ultrafiltration of lignosulphonates, which simulates a real industrial filtration problem in the pulp and paper industry. Cleaningwas undertaken with both an acid and a commercial aqueous cleaning formulation. Results are presented which show that cleaning performance is strongly dependent upon the nature of the foulant. Results also illustrate the importance of examining membrane performance over several fouling and cleaning cycles.