| 1. |
- Essalhi, Mohamed, et al.
(författare)
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The potential of salinity gradient energy based on natural and anthropogenic resources in Sweden
- 2023
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 215
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents assessment of natural and anthropogenic sources of blue energy within Swedish territory to identify suitable spots for implementing new projects. The natural energy potential of salinity gradients was found to be higher in southwest Sweden, and a national energy resource potential of 2610.6 MW from seawater/river water mixing will be reduced to a technical potential ranging from 1044.3 MW to 1825.4 MW considering technical and environmental constraints. It has been found that the theoretical extractable energy potential in Sweden is equivalent to 13% of the total electricity consumption and 6.2% of the total final energy consumption by energy commodities.Anthropogenic water sources were also highlighted as promising low and high-concentration solutions for SGE extraction. Gotland was identified as an attractive location for generating salinity gradient power. The total salinity gradient power obtainable by mixing municipal wastewater with seawater in Sweden was estimated to be 11.8 MW. The most promising site for this process was determined to be Gryaab AB Ryaverket in Gothenburg, which accounted for 45.8% of the total national potential from anthropogenic sources.
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| 2. |
- Rudolph, Gregor, et al.
(författare)
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Investigations of alkaline and enzymatic membrane cleaning of ultrafiltration membranes fouled by thermomechanical pulping process water
- 2018
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Ingår i: Membranes. - : MDPI AG. - 2077-0375. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- The pulp and paper industry is one of the most important industrial sectors worldwide, and has considerable potential for the sustainable fractionation of lignocellulosic biomass to provide valuable compounds. Ultrafiltration (UF) is a suitable separation technique for the profitable production of hemicelluloses from process water from thermomechanical pulping (ThMP), but is limited by membrane fouling. Improvements in cleaning protocols and new alternative cleaning agents are required to ensure a long membrane lifetime, and thus a sustainable process. This study, therefore, focuses on the cleaning of polymeric UF membranes after the filtration of ThMP process water, comparing alkaline with enzymatic cleaning agents. The aim was to develop a cleaning procedure that is efficient under mild conditions, resulting in a lower environmental impact. It was not possible to restore the initial permeability of the membrane when cleaning the membrane with enzymes alone, but the permeability was restored when using a two-step cleaning process with enzymes in the first step and an alkaline cleaning agent in the second step. Scanning electron microscopy gave a deeper inside into the cleaning efficiency. Attenuated total reflectance Fourier-transform infrared spectroscopy analysis confirmed that not only polysaccharides, but also extractives are adsorbed onto the membrane surface.
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| 3. |
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34th EMS Summer School : Membranes in Biorefineries
- 2017
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Proceedings (redaktörskap) (refereegranskat)abstract
- The EMS Summer School “Membranes in Biorefineries” is related to Annex XVII of the Industrial Energy Related Technologies and Systems (IETS)Implementing Agreement: “Membrane Filtration for Energy-efficient Separation of Lignocellulosic Biomass Components” co-ordinated by the Department of Chemical Engineering at Lund University, Sweden.The IETS Implementing Agreement is an initiative within IEA (International Energy Agency). The mission of IETS is to foster international co-operation among OECD and non-OECD countries for accelerated research and technology development of industrial energy-related technologies and systems. In doing so, IETS seeks to enhance knowledge of cost-effective new industrial technologies and system layouts that enable increase productivity and better product quality while improving energy efficiency and sustainability.
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| 4. |
- Bildyukevich, Alexandr V., et al.
(författare)
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Effect of molecular weight of polyacrylic acid (PAA) on polyethersulfone membrane structure and performance
- 2019
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Ingår i: ; , s. 88-88
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Konferensbidrag (refereegranskat)abstract
- The novel method of modification of polyethersulfone (PES) ultrafiltration membranes is proposed. This method involves the use of aqueous solutions of polyacrylic acid (PAA) of different molecular weights (Mn=5.1×103 g·mol–1, Mn=490×103 g·mol–1) as a coagulant in non-solvent induced phase inversion process (NIPS). Addition of PAA (0.05–1.5 wt%) to the coagulation bath leads to marked changes in permeability and hydrophilicity of the surface of membrane selective layer. When the coagulation bath contains 0.5 wt% of PAA (Mn=5.1×103 g·mol–1) the rejection coefficient for polyvinulpyrrolidone (PVP К-30, Mn=40 kDa) decreases from 95% (for pristine PES membrane) to 80% (for membrane modified by PAA) and pure water flux (PWF) increases from 55 to 150 l·m-2·h-1. The presence of 0.1 wt% PAA (Mn=490×103 g·mol–1) in the coagulation bath results in an increase in PWF up to 220 l·m-2·h-1 and a decrease in rejection coefficient down to 35%. Water contact angles of the surface of the selective layer of modified membranes decreased down to 33o, for membranes, modified with PAA of higher molecular weights, and down to 43o for for membranes, modified by PAA with lower molecular weight (Mn=5.1×103 g·mol–1). The presence of PAA on the surface of PES membranes is confirmed by the FTIR spectroscopy. The membranes obtained by using PAA solution were pH-sensitive and pH-reversible, while the PWF of the initial membranes did not respond to the pH of feed solution. The SEM analysis of the structure of the membranes reveals marked difference in the morphology along cross section between the pristine and modified membranes. The suppression of macrovoids formation in the supporting layer of membrane with an increase in the concentration of PAA in the coagulation bath was noted. Fouling resistance behavior was studied using bovine serum albumin (BSA) solution in phosphate buffer. It was found that PAA addition to the coagulation bath enhances the fouling resistance of the modified membranes. The best fouling resistance with respect to BSA fouling is observed for the membranes with maximum hydrophilicity.This work was supported by the Belarusian Republican Foundation for Fundamental Research, Grant No. X18MС-018 and STINT Grant no. IB 2017-7377.
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| 5. |
- Burts, Katsiaryna S., et al.
(författare)
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Development of Antifouling Polysulfone Membranes by Synergistic Modification with Two Different Additives in Casting Solution and Coagulation Bath: Synperonic F108 and Polyacrylic Acid
- 2022
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- This study deals with the development of antifouling ultrafiltration membranes based on polysulfone (PSF) for wastewater treatment and the concentration and purification of hemicellulose and lignin in the pulp and paper industry. The efficient simple and reproducible technique of PSF membrane modification to increase antifouling performance by simultaneous addition of triblock copolymer polyethylene glycol-polypropylene glycol-polyethylene glycol (Synperonic F108, Mn =14 × 103 g mol−1) to the casting solution and addition of polyacrylic acid (PAA, Mn = 250 × 103 g mol−1) to the coagulation bath is proposed for the first time. The effect of the PAA concentration in the aqueous solution on the PSF/Synperonic F108 membrane structure, surface characteristics, performance, and antifouling stability was investigated. PAA concentrations were varied from 0.35 to 2.0 wt.%. Membrane composition, structure, and topology were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The addition of PAA into the coagulation bath was revealed to cause the formation of a thicker and denser selective layer with decreasing its pore size and porosity; according to the structural characterization, an interpolymer complex of the two additives was formed on the surface of the PSF membrane. Hydrophilicity of the membrane selective layer surface was shown to increase significantly. The selective layer surface charge was found to become more negative in comparison to the reference membrane. It was shown that PSF/Synperonic F108/PAA membranes are characterized by better antifouling performance in ultrafiltration of humic acid solution and thermomechanical pulp mill (ThMP) process water. Membrane modification with PAA results in higher ThMP process water flux, fouling recovery ratio, and hemicellulose and total lignin rejection compared to the reference PSF/Synperonic F108 membrane. This suggests the possibility of applying the developed membranes for hemicellulose concentration and purification.
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| 6. |
- Burts, K.S., et al.
(författare)
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Development of polysulfone ultrafiltration membranes with enhanced antifouling performance for the valorisation of side streams in the pulp and paper industry
- 2022
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 632
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Tidskriftsartikel (refereegranskat)abstract
- One-stage method of polysulfone (PSf) membrane modification by the addition of polyacrylic acid (PAA, Mn = 250 kg·mol−1) to the coagulation bath during membrane preparation via non-solvent induced phase separation (NIPS) was proposed. The effect of PAA concentration on the membrane structure, hydrophilicity, zeta potential, separation performance and antifouling stability in ultrafiltration of lysozyme, polyvinylpyrrolidone (PVP K-30, Mn = 40 kg mol−1) and humic acid model solutions as well as thermomechanical pulp mill process (ThMP) water was studied. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), measurements of the tangential flow streaming potential and water contact angle were used for membrane characterization. It was found that addition of PAA into coagulation bath resulted in decreasing pore size and porosity of the selective layer as well as the formation of a thicker and denser selective layer. Water contact angle of the modified membranes was found to decrease significantly and zeta potential of the selective layer was shown to become more negative in the studied pH range 3–10, all compared to the reference membrane. It was revealed that pure water flux (PWF) decreased and lysozyme and PVP K-30 rejection increased with the increase in PAA concentration in the coagulation bath. It was found that membranes modified with PAA demonstrated better antifouling stability in ultrafiltration of humic acid solution and ThMP process water. Modified membranes were found to have higher flux, fouling recovery ratio and hemicelluloses rejection in ThMP process water ultrafiltration compared to the reference PSf membrane that allows application of these membranes for hemicelluloses concentration and purification.
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| 7. |
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Current Trends and Future Developments on (Bio-) Membranes
- 2024
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Current Trends and Future Developments on (Bio-) Membranes: Engineering with Membranes discusses various aspects of membrane engineering. This includes, but is not limited to, the role of membranes in food production, treatment and recovery, their applications in electrochemical processes and devices, in drug delivery and in ionic materials, such as salts, acids and bases, recovery. In addition, this book approaches the above topics in a different angle than the existing publications, i.e., reviews technical difficulties, environmental challenges and economic analysis. Membranes are one of the technologies which can affect various aspects of engineering dealing with feeds and products. Membranes demonstrate selective purifying properties, hence, membranes can help in the removal of various pollutants onsite and without the need of adding extra units and apparatuses. Besides that, membranes help reactions shift forward and make the whole process more efficient.
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| 8. |
- Danielsson, Sverker, et al.
(författare)
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A novel approach for applied membrane filtration on processing flows
- 2012
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Konferensbidrag (refereegranskat)abstract
- Membrane filtration technique shows exclusively properties for optimized filtration for a given size, from micrometer to nanometer scales compared to other industrial filtration. However, there is a trade off in flux that has delayed the implementation of the membrane techniques for a wider range of applications. For a specific flow in a process stream, the limited flux through the membrane means large membrane area is demanded, that results in a return of investments not accepted by industry. On the other hand, as the energy prices increases and environmental issues become more and more important as design parameters, the membrane techniques will due to its excellent separation performance be of interest, and from a life cycle analysis (LCA) a feasible approach.In this project the process flows in pulp and paper sector, and in particular the waste water treatment, are studied based on membrane technology. The purpose is to obtain a procedure to evaluate the membrane technique so that the results are guiding for extended studies. Two different representative integrated mills have been in focus, one thermo-mechanical pulp mill and one kraft pulp mill. The waste water streams that result in challenges for treatment process and that due to membrane filtration give reject / accept of greater values are studied. The possible benefit is two-fold the waste can be used as a resource of added valued products and the energy demanding waste water treatment decreases.A membrane filtration equipment from Alfa Laval LabStak M20 was used in this study on different streams for a pulp and paper mill. In this unit several membranes can be tested at the same time in order to briefly evaluate a type of membrane which suitable for the prevailing conditions, ranging from RO, NF, UF and MF depending on molecular weight cut-off (MWCO) and pore size. The volume concentrations factor (VFC) ranged from 1-4 in this study and the reduced TOC indicates satisfactory results. As pointed out, a trade off in decrease flux during filtration was in the order of 20%, to be considered in process design. The result gives indication of feasible way to use membrane filtration techniques as a tool for creating new business opportunities and elucidate the potential in reducing the water and energy consumption. The technique is demonstrated to gained parameters of importance for the pulp and paper sector. However, also applicable for other industry sectors when dealing with large scale processing flows
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| 9. |
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| 10. |
- Elhamarnah, Yousef, et al.
(författare)
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Investigating the impact of stormwater fouling on polysulfone ultrafiltration membranes modified with deep eutectic solvents
- 2023
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Ingår i: Journal of Water Process Engineering. - 2214-7144. ; 56, s. 104362-104362
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we evaluate the performance of modified polysulfone (PSF) ultrafiltration (UF) membranes, which incorporate deep eutectic solvents (DES), in treating stormwater laden with natural organic matter e.g. chemical oxygen demand (COD) and total suspended solids (TSS). We also aim to understand how these organic substances, e.g. COD, TSS, from the water source contribute to the fouling of the synthesized membranes. PSF membranes were synthesized using a non-solvent induced phase separation technique and integrated with varying concentrations of ChCl:FR (Choline Chloride: D-(−)-Fructose) 1:1 DES. The surface and porous structures of the membranes were characterized through Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurements, scanning electron microscopy (SEM), and mechanical testing. The UF performance of these membranes was assessed and compared with different commercially available UF flat sheet membranes in terms of pure water permeability and antifouling behavior against collected stormwater from a sedimentation pond. Furthermore, the study evaluated the quality of the permeate based on parameters such as COD, turbidity, TSS, pH, and conductivity and compared the permeate quality of a pilot-scale ceramic UF membrane unit. The findings indicate that the inclusion of DES in the polysulfone membrane structure enhances the membranes' antifouling properties and permeability. This research offers valuable insights into the role of DES in the formation of polysulfone UF membranes and their potential for practical use e.g. sedimented stormwater.
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