Maximizing power density generation from seawater via pressure retarded osmosis (PRO) using commercially available membranes Ziran Su, Mie Thoendal Pedersen, Klaus Karlsen, Haofei Guo, Lars Storm Pedersen, Magdalena Malankowska, Manuel Pinelo Chemical Engineering Research and Design, 2026 Pressure retarded osmosis (PRO) is a green technology for harvesting Gibbs free energy from mixing solutions with different salinity gradients. Although lab-synthesized membranes showed high PRO performance, there is no available flat-sheet industrial-scale PRO membrane production. Most of the previous studies have focused on enhancing the power density of the PRO process by using a hypersaline draw solution that potentially causes severe internal and external concentration polarization (ICP and ECP) and limits achievable performance. Using the most accessible resources – seawater and commercially available membranes – can be a more practical way to develop a large-scale PRO plant. However, only a limited number of studies have evaluated the PRO performance under such realistic conditions. In our study, we compared the PRO performance of some commercial FO and RO membranes. We observed that, at an elevated feed velocity and temperature, the RO membrane had a significant enhanced water flux and power density. Due to turbulent flow at a high feed velocity and low viscosity at a high feed temperature (30 °C), the RO membrane was able to perform at low concertration polarization, hence maximum power density (5.3 W/m 2 ) could be obtained at half the osmotic pressure (15 bar). • Seawater and commercial RO and FO membranes were used for PRO • An elevated feed velocity and temperature resulted in high power density • Commercial RO membranes outperformed FO membranes in the PRO tests • 5.3 W/m 2 was achieved at 15 bar using a commercial RO membrane
Magnetically Recoverable δ-FeOOH Particles for Multilayer Enzyme Immobilization and Surface-Induced Activity Tuning Francisco Lucas Chaves Almeida, Ederson Paulo Xavier Guilherme, Maria Isabel Rodriguez-Torres, Laura Rotilio, Magdalena Malankowska, Aliyeh Hasanzadeh, Bodil Fliis Holten, Suzana Siebenhaar, Lars Michael Skjolding, Jens P. Morth, John M. Woodley, Marcus Bruno Soares Forte, Elif Erdem ACS Omega, 2025 High Resolution Image Download MS PowerPoint Slide Enzyme immobilization is an effective strategy to enhance enzyme stability, which remains a major drawback in biocatalysis. However, achieving high enzyme loading without loss of activity is still a key limitation of conventional support. Most supports that overcome these limitations, such as nano- and microparticles, involve high production costs. Therefore, a support that combines the advantages of high surface area, easy recovery, and low-cost production is still lacking in the literature. In this study, we present a low-cost, dual-function, magnetically recoverable support material, superparamagnetic δ-FeOOH (feroxyhyte) particles, that enhances enzyme activity and modulates protein structure both prior to, and following immobilization. We show that δ-FeOOH enables lipase immobilization at loadings exceeding 60 mg g –1 while maintaining activity and structural integrity. Circular dichroism and fluorescence analyses reveal support-induced conformational changes, decreased α-helicity and increased β-sheet content, that do not impair enzymatic performance. Zeta potential analysis further confirms progressive surface saturation and multilayer formation, with continued adsorption beyond ∼40 mg g –1, without functional decline. Notably, both lipase and NADH oxidase (L p NOX) exhibit up to 1.3-fold activity enhancement in the presence of δ-FeOOH, even in the absence of covalent binding, suggesting a surface-induced activation mechanism. Together, these findings establish δ-FeOOH as a high-capacity, structurally tunable enzyme support. Its ability to promote both immobilization and functional enhancement makes it a promising platform for next-generation biocatalysts in continuous, high-density, and multienzyme systems.
Hydrophobic deep eutectic solvents as novel, sustainable aids for intracellular protein release from Saccharomyces cerevisiae Tjalling Gijsbert Tjalsma, Yannick Patrice Didion, Ziran Su, Magdalena Malankowska, Pablo Torres-Montero, José Luis Martínez, Manuel Pinelo Results in Engineering, 2025 • DESs were synthesized from natural compounds. • DES exposure to S. cerevisiae can result in improved intracellular protein release. • The properties of DESs for effective protein release were discussed. Saccharomyces cerevisiae ( S. cerevisiae ) is a microorganism of high interest due to its applications in pharmaceutical and food industries. However, traditional downstream processing of intracellular compounds often depends on organic solvents and harsh processing conditions. Here, the use of hydrophobic deep eutectic solvents (DESs) as cell wall permeabilization agents for intracellular protein release from Saccharomyces cerevisiae was studied for the first time. This study examines the relatively new type V DESs, which favors downstream methods because less solvent is needed and environmentally friendly substances can be used. The DESs were synthesized from L-menthol, lidocaine, acetic acid, decanoic acid, oleic acid and lauric acid, and screened for viability. Next, 0.5 wt% DES was mixed in a mild alkaline buffer containing S. cerevisiae . Despite the similar structures of the hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD), DESs with L-menthol and lidocaine as HBA and a fatty acid as HBD exhibited superior performance compared to DESs consisting solely of L-menthol and lidocaine or those derived from fatty acids only. DES lidocaine:decanoic acid 1:3 resulted in a protein yield of 2.45 (±0.03) mg/mL, which outperformed a method using a standard lysis reagent that resulted in 2.33 (±0.04) mg/mL. It was concluded that the underlying linkages between HBA and HBD play a key role because different HBA and HBD combinations have a bearing on whether protein release is successful.
Integrating metal organic frameworks (MOFs) and polyelectrolytes (PEs) in membrane reactors for boosting the activity of immobilized carbonic anhydrase Magdalena Malankowska, Andrei Popkov, Markus DeMartini, Gustav Jørgensen, Ziran Su, Manuel Pinelo Chemical Engineering Journal, 2024 • Carbonic anhydrase (CA) successfully encapsulated in ZIF-8. • CA successfully immobilized on an ultrafiltration membrane. • Membrane dual reactor with CA encapsulated in MOF was developed. • The immobilized CA showed increase in activity and thermostability. Atmospheric CO 2 levels are now at their highest point and the remediation technology is being actively explored. Carbonic anhydrase (CA) is the enzyme that can help sequester CO 2 from industrial processes. However, enzyme stability under these industrial conditions is a big disadvantage. Herein, we propose a novel dual reactor where we combine an Enzymatic membrane reactor (EMR) with enzyme encapsulation in Metal-organic-framework (MOF) inside one unit − by employing various attachment mechanisms and using polyelectrolytes in different multilayer configurations. The polydopamine (PDA)-assisted co-deposition approach was used for modification of pristine polysulfone membranes. Each immobilization method was evaluated individually first, i.e.: enzyme immobilized on a membrane, enzyme encapsulated in MOF, and the dual reactor. In this work, immobilization of CA on a modified membrane surface showed a 2.5-fold increase of enzyme specific activity (558 vs 220 mU/mg), while encapsulation of CA in MOF significantly improved its thermal stability (11 % vs 92 % of CA activity loss upon incubation at 60 °C). Enzyme immobilized in the dual reactor demonstrated biocatalytic activities up to 744 µU/cm 2 while retaining up to 59 % of the native membrane permeability. The results shown in this work present the proof of concept of effective integration of MOFs and EMRs to enhance the performance of immobilized CA. Finally, this work shows that selected CA immobilization methods can promote significant increases of activity, particularly at high temperatures, and therefore immobilization cannot only be used for boosting enzyme stability but also activity. This research can pave the way for future exploration of different possibilities for the use of enzymes and methods of their protection without decreasing their performance.
Novel membrane modifications for pressure retarded osmosis as a new way for sustainable power generation from salinity gradients Magdalena Malankowska, Ziran Su, Klaus Karlsen, Martin Flaskjær Buhl, Haofei Guo, Lars Storm Pedersen, Manuel Pinelo Chemical Engineering Science, 2024 Pressure retarded osmosis (PRO) is a novel technology that allows power to be generated from high-salinity resources. To achieve a high power density, a high-salinity solution should be used on the draw side together with high hydraulic pressure, thus the PRO process requires a membrane that has high salt rejection and high pressure resistance. The reverse osmosis (RO) membranes can be potential candidates for the PRO process. In this study, commercial RO membranes with different surface modifications were examined: O2 plasma, polydopamine (PDA) and tannic acid (TA). Improved water permeability and salt rejection were obtained after modification. The membranes were also tested with a high salinity solution (175 g/L NaCl) in a PRO mode. Due to the improved water permeability and high salt rejection of the surface-modified membrane, the commercial RO membrane showed enhanced power density (3 W/m2) in comparison to the pristine membrane (2 W/m2).
Opting for polyamines with specific structural traits as a strategy to boost performance of enzymatic membrane reactors Andrei Popkov, Magdalena Malankowska, Markus Simon De Martini, Shantanu Singh, Ziran Su, Manuel Pinelo Chemical Engineering Journal, 2024 Enzymatic membrane reactor (EMR) is a type of continuous-flow bioreactor offering easy separation and reuse of biocatalyst while giving opportunities to improve its performance. However, simultaneous enhancement of activity and stability of enzyme while retaining high membrane permeability poses a challenge for a single reactor. Herein, we propose a new method to optimize EMR system − by employing cationic polyelectrolytes with selected molecular weight, backbone, and amino group type for modification of membrane surface; after we have evaluated the effect of polyamine chemistry and membrane properties on each aspect of EMR performance. Polydopamine (PDA)-assisted co-deposition of polyamines (polyethyleneimine (PEI), PEI-graft-poly(ethylene glycol) (PEI-g-PEG), poly(allylamine hydrochloride) (PAH), and poly(diallyldimethylammonium chloride) (PDADMAC)) was used as the modification method; the membranes were characterized by water permeability, water contact angle (WCA), zeta potential (ZP), FTIR spectra, and SEM/EDX; and EMRs were assessed by biocatalytic activity at various pH, flux, immobilization yield and efficiency (activity recovery), enzyme leakage, pH/storage and thermal stability, and reusability. In this work, EMRs with immobilized alcohol dehydrogenase (ADH) showed activities up to 8.9 mU/cm2, retained up to 86 % of initial activity in three conversion cycles without any reduction in flux, and allowed to increase non-optimal pH activity (pH 10) by up to 81 % and improve storage stability by up to 53 % compared to the free enzyme. We discovered statistically significant (p < 0.01) relationships between: (1) polyamine backbone type (linear vs branched) and membrane permeability; (2) membrane isoelectric point and immobilization yield; and (3) membrane WCA and immobilization efficiency. To our knowledge, this is the first systematic study of the effect of polyelectrolyte chemistry on performance of immobilized enzyme − which showed the method’s strong potential for customizing properties and maximizing the productivity of EMRs.
A novel strategy for extraction of intracellular poly(3-hydroxybutyrate) from engineered Pseudomonas putida using deep eutectic solvents: Comparison with traditional biobased organic solvents Yannick Patrice Didion, Maria Victoria Gracia Alvan Vargas, Tjalling Gijsbert Tjaslma, John Woodley, Pablo Ivan Nikel, Magdalena Malankowska, Ziran Su, Manuel Pinelo Separation and Purification Technology, 2024 Polyhydroxyalkanoates (PHAs) represent a category of microbial polyesters that offer both biodegradability and biocompatibility, if produced in sufficient quantities, they could serve as an alternative to many conventional plastics in use today. However, these microbial polymers are intracellularly stored, necessitating a more complex downstream extraction and purification process. Downstream processes often constitute the most financially burdensome stage in biomolecule production. One significant drawback of many existing extraction processes is their reliance on harsh organic solvents, such as chloroform, and high temperatures. This study presents and compares two novel downstream processes for the extraction and purification of poly(3-hydroxybutyrate) (PHB), a type of short-chain-length PHA, utilizing bio-based green solvents and natural deep eutectic solvents (NADES), respectively. The soil bacterium Pseudomonas putida, engineered to produce PHB from sugars, was adopted as a model for testing these extraction procedures. Initially, biomass was disrupted using a hypotonic buffer containing lysozyme to enhance the extraction efficiency in the downstream process. After extensive screening, the bio-based solvent ethyl acetate was selected for PHB extraction from P. putida biomass, yielding ∼ 95 wt% of the homo-polymer with a purity of ∼ 97 wt%, results comparable to those achieved with the traditional benchmark solvent, chloroform. Furthermore, a hydrophobic natural deep eutectic solvent (hydrophobic NADES) was synthesized, comprising L-menthol and acetic acid in a 1:3 M ratio, and employed as the extraction solvent in combination with methanol as the anti-solvent. The optimized extraction process resulted in a homo-polymer yield of ∼ 66 wt% with a high purity of ∼ 85 wt%. These results are promising considering the benefits associated with the use of NADES, they are less toxic and much easier to handle than ethyl acetate and have the potential to be recycled. Therefore, it represents a promising avenue for a more sustainable PHB extraction process, devoid of harmful organic solvents.
Novel membrane coating methods involving use of graphene oxide and polyelectrolytes for development of sustainable energy production: Pressure Retarded Osmosis (PRO) and Enzymatic Membrane Reactor (EMR) Ziran Su, Magdalena Malankowska, Jonas Sterup Brigsted, Andrei Popkov, Haofei Guo, Lars Storm Pedersen, Manuel Pinelo Chemical Engineering Research and Design, 2024 This study compares pressure retarded osmosis (PRO) and the enzymatic membrane reactor (EMR) for the production of green energy in the form of power density and biomethanol, respectively. A systematic design of the biocatalytic membrane reactor and the PRO membrane system was carried out where we combined physical adsorption of polyelectrolyte (PE) and the graphene oxide (GO) layer-by-layer (LbL) assembly system. The hybrid LbL structure is proposed as a strategy to simultaneously advance the operational stability of the enzymes in the EMR and to increase hydrophilicity and power density in the PRO approach. Using polydopamine (PDA), poly(diallyldimethylammonium chloride) (PDADMAC) and GO allowed functionalization of polysulfone (PSF) membranes for subsequent Alcohol Dehydrogenase (ADH) immobilization in the EMR and functionalization of polyamide (PA) membranes for PRO. Tailoring membrane surface chemistry allowed an increase in enzyme conversion rate in comparison to the pristine, unmodified membrane (99.6% vs 2%, respectively) without significantly compromising water permeability. Moreover, power density increased from 2.10 to 2.64 W/m2 for pristine and modified membrane, respectively. Energy production in kJ/m2·h was compared and the most efficient technology was chosen.
Comparison of 2D and 3D materials on membrane modification for improved pressure retarded osmosis (PRO) process Ziran Su, Magdalena Malankowska, Thomas Marschall Thostrup, Markus DeMartini, Peyman Khajavi, Haofei Guo, Lars Storm Pedersen, Manuel Pinelo Chemical Engineering Science, 2024 Pressure retarded osmosis (PRO) is a sustainable process that convert Gibbs free energy to osmotic energy by mixing two solutions of different salinities. The main challenges in the design of PRO membranes are obtaining a membrane with high water permeability and low salt permeability but also very high mechanical strength because the PRO process involves high pressure on the draw solution. Commercially available RO membranes with potential utility in a PRO system exhibit a high salt rejection rate but low water permeability and mechanical stability. Surface modification is a promising strategy for tuning the fundamental properties of the membranes (e.g. hydrophilicity, surface charge and thickness) that can improve the filtration performance of the membranes. The coating layer can also improve the mechanical stability of the membranes. Therefore, in this work, various types of modification materials were applied to the commercial available RO membranes to enhance their performance. With the assistance of hydrophilic materials (e.g. polydopamine – PDA), filtration performance of the membranes can be increased through membrane modification by 2D materials with high charge intensities (e.g. polyelectrolytes and graphene oxides) and by 3D mesoporous materials (e.g. zeolites), which increases the thickness of the membrane that can be beneficial in mechanically reinforcing the membrane. In this work, we modified commercial RO membrane with PDA, polyelectrolytes, graphene oxide and zeolites (ZSM-5). Improved filtration performance (increased water permeability and maintained salt permeability) of the modified membrane was observed. Tensile tests showed enhanced mechanical strength of the modified membranes, especially following 3D zeolites modification (up to 35 % of higher tensile strain was reported). Interestingly, a lower concentration of PDA (2 mg/mL) and zeolites resulted in higher mechanical strength of the modified membranes. Such results were likely due to a more homogenous coating layer when a low modifier concentration was applied. The thin and uniform layer can better absorb energy when membranes are under high pressure.
Membrane sensors for pollution problems S. Mondal, M. Malankowska, A.H. Avci, U.T. Syed, L. Upadhyaya, S. Santoro Current Trends and Future Developments on Bio Membranes Membrane Technologies in Environmental Protection and Public Health Challenges and Opportunities, 2022
3D-fractal engineering based on oxide-only corner lithography J.W. Berenschot, R.M. Tiggelaar, J. Geerlings, J.G.E. Gardeniers, N.R. Tas, M. Malankowska, M.P. Pina, R. Mallada Symposium on Design Test Integration and Packaging of MEMS Moems Dtip 2016, 2016
