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Student assignments

Information on student assignments with MST

Looking for an assignment? Please contact us for the possibilities at the Membrane Science & Technology cluster. Below are our vacant  student assignments. 

  • Micropollutant removal from municipal wastewater with membranes modified with zipper brushes (MSc/BSc assignment)

    Keywords: Materials science, surface chemistry, ion retention, fouling control

    For more information please contact: Wendy Jonkers (

    Organic micropollutants are small, synthetic organic compounds from agriculture (pesticides), industry (plasticizers), hospitals (pharmaceuticals) and domestic life (personal care products). These compounds are present in low (ng - μg) concentrations in municipal wastewater and cannot be fully removed by traditional wastewater treatment plants (WWTPs).  Consequentially, these compounds often end up in our surface waters, and might even end up in drinking water. Already, the presence of micropollutants in surface waters has become problematic as they can have severe environmental effects, even at low concentrations.

    One of the ways to counter this issue is using nanofiltration membranes at the wastewater treatment plants to filter out the micropollutants. These membranes can remove micropollutants to a high extent (~98%). However, an issue of nanofiltration membranes is that they also retain salts. This salt retention is however undesired an could lead to scaling and a reduced efficiency of the microorganisms in the WWTP, while one would also need to remineralize the clean permeate water.

    The goal of this project is to reduce ion retention in nanofiltration membranes in order to make them more relevant to wastewater treatment. To achieve this, you will modify donnan exclusion-dominated membranes with zipper brushes. In donnan exclusion-dominated membranes, ion rejection mainly takes place at the charged membrane surface. We propose modifying the membrane surface with zipper brushes, to create a more neutral surface. Previous research in our cluster indicated that favorable membrane properties such as high permeability and low MWCO could be retained with this method. An additional advantage of this method is that zipper brushes have anti-fouling properties. This modification could therefore possibly both reduce ion retention and extend membrane lifetime, which would make them cheaper and more suitable for organic micropollutant removal from waste water.

    During this project, you can focus on:

    1. Preparation of Nanofiltration membranes by coating support membranes with polyelectrolytes according to the layer-by-layer technique
    2. Modification of membranes by coating zipper brushes on top of the polyelectrolyte membrane surface
    3. Characterization of the membranes with crossflow measurements, GPC, reflectometry and zeta-potential measurements and naturally organic micropollutant retention
    4. Assessment of fouling behavior and stability of the membranes by exposure to fouling- and cleaning agents.
  • Starting up and investigating a biological wastewater treatment plant with recirculation of nanofiltration concentrate to remove organic micro-pollutants

    What happens if you take a painkiller like paracetamol? Part of the substance will be used to indeed relieve your pain, but your body does not degrade the chemical completely. Therefore, you will excrete part of it and send that part to the sewage. Our current wastewater treatment plants are however not designed to remove all medicine like the painkillers, but also all kinds of other chemicals. These components are called organic micro-pollutants (OMPs) and lead to growing awareness and concern. OMPs have the potential to cause long-term harm to humans and the environment. Therefore, a novel nanofiltration membrane is developed that discharges very clean water from wastewater treatment plants, free from OMPs. A membrane however also creates a concentrate (waste stream) that needs to be treated which contains elevated concentrations of OMPs. This project focuses on the application of the membrane on pilot scale (1 m3/hr), with a recycle of the concentrate to a biological wastewater treatment system, as depicted in Figure 1. This biological treatment system is also part of the pilot. The pilot is running from the fall of 2021 onwards. In this assignment, you will have the opportunity to contribute to the start-up or operation of the pilot at the wastewater treatment plant of Enschede, and with that, to the future of wastewater treatment!

    Figure 1: schematic overview of the process with on the left a typical wastewater treatment plant, and at the right the membrane. The pilot plant will contain the full process as depicted here.

    Your tasks can include:

    • Assisting in delivery and commissioning of the pilot
    • Ensuring that operation protocols are good
    • Ensuring smooth operation of the pilot plant and tackling operational issues
    • Analyzing the performance of the pilot plant by (1) taking samples & analyzing these samples yourself and (2) analyzing the data that the pilot plant will produce continuously
    • Communicating about your findings with both involved universities (Wageningen University & Research and University of Twente) and companies (membrane producer NX Filtration, several water boards, technology supplier Nijhuis Industries)

    The assignment is suitable for an internship (also for students of a university of applied sciences) and can be extended to a graduation assignment as well.

    You will have the opportunity to bring forth your own ideas to be implemented in the operation. We are looking for a student that can communicate well (preferably both in Dutch & English), is able to work independently and has a hands on, problem solving attitude. You will be working in Enschede, mainly at the wastewater treatment plant of Enschede and at the UT.

    If you have any questions about the assignment, please contact Hans David Wendt at

  • Photocatalytic degradation of glycerol in a microchannel (MSc assignment)


    Microreactors are well known to intensify a process. Higher conversion can be achieved by changing the reactor from a slurry reactor to a microreactor. It’s easier to determine what is happening in the channel and taking it into account due to the laminar flow. Kinetics can be identified as what is happening at the surface instead of in the bulk. Therefore, microreactors are the ideal platform to study different parameters which influence the kinetics of organic oxidation reactions. Parameters which could influence the kinetics are pH, temperature, oxygen concentration, and others. The microchannel is schematically shown in the figure below, adjusted from [1].


    Project scope

    In this project, the focus is on the influence of the light source on a photocatalytic reaction, which is the oxidation of glycerol to more valuable products. In combination with some modelling you’ll try to figure out what is happening in the channel at the catalytic wall. The experimental part will consist of conversion experiments, to measure how much is converted and into what. A second experimental part consists of fluorescence lifetime imaging microscopy, where real-time profiles of oxygen, pH, carbon dioxide and temperature can be made over the length of the channel.


    For more information, feel free to contact Nicole Timmerhuis (


    [1] Rafieian, D., Driessen, R. T., Ogieglo, W., & Lammertink, R. G. (2015). Intrinsic photocatalytic assessment of reactively sputtered TiO2 films. ACS applied materials & interfaces7(16), 8727-8732.

    This project can also be executed by a bachelor student, but preference is given to a master student.

  • Pressing PECs to Plastics: Exploring polyelectrolyte combinations for ion-exchange applications

    Ameya Krishna Bysani1,2,*, Saskia Lindhoud2, Wiebe M. de Vos1

    Membrane Surface Science, Membrane Science and Technology, Universiteit Twente

    NanoBioPhysics, MESA+ Institute, Universiteit Twente


    Keywords: Materials Science, Polyelectrolyte complex (PEC), Saloplastic, Membrane, Ion-exchange, Electrodialysis

    Let me introduce you to the topic!

    Polyelectrolytes (PEs) are water-soluble polymers containing fixed charges in their chains. They are particularly interesting in a scenario where oppositely charged PEs combine to form a polyelectrolyte complex (PEC). PE pairs combine in specific ratios which makes their properties extremely interesting.  Few combinations have been explored yet, and the possibilities are promising!

    Films are made using these complexes, and a net charge on them allows us to explore their prospects as ion-exchange membranes (IEMs). IEMs are a class of dense semi-permeable membranes that are electrically conductive. Ideally, they allow the passage of counterions and reject co-ions.  This property is called permselectivity. Electrodialysis is used to determine the electrical resistance and other properties.

    Why is this awesome?

    Polyelectrolytes can be versatile, charge-controlled, complexed, and coated. Further, characteristics of PECs open many doors and their applications can be simple, inexpensive, and sustainable alternatives to several existing materials. Membranes are no exception. PEs have been used to successfully make micro-, nano-, and ultra-filtration membranes. Their use as IEMs can be extremely beneficial in desalination, water softening, and wastewater treatment to name a few!

    Figure: Polyelectrolyte complexes to Ion-exchange membranes

  • Diffusio-osmosis, an engineering approach (MSc assignment)


    Many heterogeneous systems have mass transfer limitations near the solid-liquid interface. These limitations in the boundary layer are due to fast reaction at the wall, creating a concentration drop towards the solid. Or it could be from the velocity which is standing still near the wall due to a laminar, parabolic flow pattern in the microchannel. The main focus of this project is to overcome this mass transfer limitation by creating an osmotic flow near the solid-liquid interface in the boundary layer.

    An osmotic flow is created by a pressure gradient in the liquid, which is directly proportional to the concentration gradient for non-electrolytes and to the natural logarithm of the concentration gradient for electrolytes [1]. The concentration gradient is created by the interaction between the liquid particles and solid interface, which can be repulsive or attractive. If different solid interfaces are used, alternating each other, a continuous osmotic flow can be created in the boundary layer along the wall. This is schematically shown in the figure below.

    Project scope

    In this project you’ll research the broader impact of diffusio-osmosis. What would be the design parameters to utilize osmotic flow for higher conversion or lower pump intensities? This could be investigated numerically. An experimental approach is also possible, where you would first come up with a possible experimental design to measure the diffusio-osmotic velocity.


    For more information, feel free to contact Nicole Timmerhuis (


    [1] D.C. Prieve, J.L. Anderson, J.P. Ebel, M.E. Lowell, J. Fluid. Mech., 148:247-269, 1984

    This project can also be executed by a bachelor student, but preference is given to a master student.

  • Influence of Ion Concentration on Polyelectrolyte Multilayer based Nanofiltration Membrane Performance (MSc assignment)


    In recent years a variety of micropollutants have been detected in ground- and surface water [1]. Micropollutants are small organic molecules with variable chemical properties that originate among others from industrial, medical and agricultural waste. Many of these molecules are highly toxic, carcinogenic or endocrine-disrupting compounds [2]. Even though the observed concentrations are still below drinking water guidelines, these micropollutants are potentially harmful to humans, organisms and the environment, as there is very little knowledge on longtime exposure and possible synergetic effects [3]. Traditional water treatment methods are not able to sufficiently remove these, therefore advanced separation technologies need to be developed to prevent them from accumulating in our water cycle [4].

    Dense membranes used in pressure-driven filtration processes such as reverse osmosis (RO) or nanofiltration (NF) are promising techniques that have been shown to retain most micropollutants [5]. The advantage of nanofiltration membranes over reverse osmosis membranes is the reduced energy cost due to lower pressures at very comparable separation performances. A relatively young and promising method to make nanofiltration membranes is to coat a very thin and selective separation layer on top of an open porous support structure using the Layer-by-Layer (LBL) method, developed by Decher in 1997 [6]. In this method polyelectrolytes of different charged are alternately coated on top of a charged substrate. The layer formation is driven by electrostatic interactions between the polyelectrolyte chains and the entropic gain of counterion release.

    Project details and outcome

    In the cluster of Membrane Science and Technology these so-called Polyelectrolyte Multilayer (PEM) membranes are developed and investigated. Depending on the membrane coating conditions the structure and with that the membrane performance, solute selectivity and solvent permeability, can be changed. At the same time, it is hypothesized, that the membrane performance directly depends on the type and concentration of ions present during filtration. In addition to ion adsorption and charge screening effects, commonly observed phenomena for nanofiltration, the PEM structure might change significantly for different ions and ion concentrations, which has been recently observed in QCM-D studies of PEM swelling behavior [7].

    The aim of this research is to investigate the influence of ion concentration on PEM performance related to structural changes. The focus will be on macroscopic transport measurements conducted with coated ultrafiltration membranes. Simultaneously structural characteristics of the multilayer, coated on a model surface, will be investigated. Following these detailed experimental studies, the applicability of a nanofiltration model based on the extended Nernst-Planck equation for the prediction of membrane retention accounting for ion adsorption, charge screening and structural changes shall be investigated.

    Your tasks:

    ·         prepare and characterize PEM hollow fiber membranes

    ·         conduct macroscopic transport measurements

    ·         investigate swelling properties for different salts and salt concentrations

    ·         apply a transport model to describe membrane performance

    For more information please contact Moritz Junker (

    1.Aa, N. G. F. M. v. d.; Dijkman, E.; Bijlsma, L.; Emke, E.; Ven, B. M. v. d.; Nuijs, A. L. N. v.; Voogt, P. d., Drugs of Abuse and Tranquilizers in Dutch Surface Waters, Drinking Water and Wastewater - Results of Screening Monitoring 2009. National Institute for Public Health and the Environment 2010.

    2.Trapido, M.; Epold, I.; Bolobajev, J.; Dulova, N., Emerging micropollutants in water/wastewater: growing demand on removal technologies. Environmental science and pollution research international 2014, 21 (21), 12217–12222.

    3.Verliefde, A.; Cornelissen, E.; Amy, G.; van der Bruggen, B.; van Dijk, H., Priority organic micropollutants in water sources in Flanders and the Netherlands and assessment of removal possibilities with nanofiltration. Environmental pollution (Barking, Essex : 1987) 2007, 146 (1), 281–289.

    4.Tröger, R.; Klöckner, P.; Ahrens, L.; Wiberg, K., Micropollutants in drinking water from source to tap - Method development and application of a multiresidue screening method. Science of The Total Environment 2018, 627, 1404–1432.

    5.Yangali-Quintanilla, V.; Maeng, S. K.; Fujioka, T.; Kennedy, M.; Amy, G., Proposing nanofiltration as acceptable barrier for organic contaminants in water reuse. Journal of Membrane Science 2010, 362 (1), 334-345.

    6.Decher, G., Fuzzy Nanoassemblies: Toward Layered Polymeric Multicomposites. Science 1997, 277 (5330), 1232–1237.

    7.O’Neal, J. T.; Dai, E. Y.; Zhang, Y.; Clark, K. B.; Wilcox, K. G.; George, I. M.; Ramasamy, N. E.; Enriquez, D.; Batys, P.; Sammalkorpi, M.; Lutkenhaus, J. L., QCM-D Investigation of Swelling Behavior of Layer-by-Layer Thin Films upon Exposure to Monovalent Ions. Langmuir 2018, 34 (3), 999-1009.

  • Organically-modified ceramic membranes for solvent tolerant nanofiltration (BSc/MSc assignment)

    Ceramic materials exhibit high thermal, chemical and mechanical stability [1]. As a result, ceramic membranes are suitable for filtration processes under harsh conditions. An interesting and upcoming separation process is nanofiltration (NF), which deals with separations on molecular level, i.e. molecules in the range of 200-1000 g mol‑1. The importance of NF processes and, by extend, of NF membranes lies on the possible recovery of valuable materials, such as transition metal catalysts and synthetic products, reuse of solvent mixtures, reduction of energy consumption for separations involving thermal treatments etc.

    NF membranes must have pore sizes of approximately 1 nm or smaller [2]. Inorganic membranes, depending on the material used, show pore sizes larger than the NF limit (ca. 1 nm). On the other hand, hybrid ceramic membranes (ceramic substrates with a covalently-grafted thin polymeric layer, operating as the membrane) have tunable pore size distributions and can be used for NF applications in chemical industry. The preparation of such membranes involves the grafting of polymeric brushes on gamma-alumina (γ-Al2O3) substrates via simple condensation reactions, in solution or in vapor phase (Figure 1). A simple reaction which, depending on the polymer used, can deliver a wide range of membranes with different properties [3,4].

    Figure 1: Grafting of phosphonic acid terminated polyethylene glycol on a γ-alumina porous support as an example of an organically-modified ceramic membrane.

    This Bachelor assignment is focused on the development and understanding of a new and simple grafting method which would allow for easy integration to industrial levels. In this project, the candidate will benefit of the expertise and equipment of the Inorganic Membranes group to develop and assess the stability as well as the performance of hybrid membranes in different media (acidic, binary solvent mixtures etc.).  A general idea for the structure of the Bachelor assignment is provided below:

    1. Fabrication of polymer-grafted membranes on porous alumina supports. The student will develop a protocol for fabrication of hybrid ceramic membranes which can be used in lab or industrial scale.
    2. Characterize the as-prepared membranes by various techniques including contact-angle, FTIR, cyclohexane permporometry, electron microscopy, HR-MAS NMR, etc…
    3. Study the performance and stability of membranes in water-solvent mixtures. Permeability and solute rejection tests.

    Skills which will be developed during the Master assignment:

    • Synthesis and understanding of the chemistry involved for fabrication of grafted NF ceramic membranes
    • Characterization of the as-prepared membranes
    •  Evaluation of the membrane performances under NF conditions (a mixture of water, solvent, and solutes)

    For more information please contact:

    Nikos Kyriakou (, Inorganic Membranes, Meander 236B

    Marie-Alix Pizzoccaro (, Inorganic Membranes, Meander 348

    Louis Winnubst (, Inorganic Membranes, Meander 348

     [1] Tsuru, T., Inorganic porous membranes for liquid phase separation. Separation and Purification Methods, 30 (2001) 191-220.

    [2] Mulder, M., Basic Principles of Membrane technology, Kluwer Academic Publishers, Dordrecht, 2nd Ed., 2004.

    [3] C.R. Tanardi, R. Catana, M. Barboiu, A. Ayral, I.FJ. Vankelecom, A. Nijmeijer, L. Winnubst. Polyethyleneglycol grafting of y-alumina membranes for solvent resistant nanofiltration, Microporous Mesoporous Mater. 229 (2016) 106–116.

    [4] C.R. Tanardi, I.F.J. Vankelecom, A.F.M. Pinheiro, K.K.R. Tetala, A. Nijmeijer, L. Winnubst. Solvent permeation behavior of PDMS grafted γ-alumina membranes, J. Memb. Sci. 495 (2015) 216–225.

  • Development of ceramic-supported 2D nanosheet membranes for Organic Solvent Nanofiltration (OSN) (MSc assignment)

    Many industrial process streams are mixtures of water, solvents and other organic components. To reuse these streams, purification is required either by conventional methods (distillation) or by use of membrane technology. Membranes can facilitate to a large amounts in cleaning waste streams, which results in significant reduction in energy and contribute to a circular economy. In this project, we aim to create a new class of solvent tolerant nanofiltration membranes consisting of two-dimensional (2D) nanomaterials.

    The interest on 2D nanomaterials (e.g. covalent-organic frameworks (COFs) or metal-organic frameworks (MOFs)) in membrane science and especially in OSN application is growing [1-3]. These materials, can offer control over the thickness and the pore size of the final organic layer. As such, membrane scientists theorize and in fact have observed through similar studies that 2D materials can significantly improve membrane permeabilities as well as selectivity [2]. These 2D-nanosheets-based membranes are typically prepared via in situ polymerization on a pre-functionalized support or via exfoliation of a premade 2D polymer material and subsequently coating on a ceramic support [1,3]. The first method implies covalent attachment between the inorganic surface and the organic framework and the second involves adsorption of the organic network on the ceramic support. Both can result in stable and selective membrane layers (Figure 1).

    Figure 1. Overview of fabrication methods for preparation of organic framework membrane chemically (left route) or physically (right route) deposited on a ceramic surface.

    In this Master assignment, the candidate will benefit of the expertise and equipment of the Inorganic Membrane group to:

    1. Preparation of ceramic-supported 2D nanosheet membranes. This method involves the preparation of a 2D polymeric material supported on a porous ceramic support via chemical or physical adsorption (Figure 1).
    2. Characterization of as-prepared membranes by various techniques like XRD, FTIR, AFM, SEM, contact angle etc.
    3. Identify key parameters that control membrane properties (thickness, adhesion to the support, etc.).
    4. Evaluate the performance of the membranes under OSN condition.

     Skills which will be developed during the Master assignment:

    • Synthesis of 2D nanomaterials and preparation of 2D nanosheet membranes
    • Characterization of the as-prepared membranes (XRD, FTIR, AFM, SEM, contact angle, DLS, etc...)
    • Evaluation of membrane performances under OSN conditions: solvents permeability and solutes rejection measurements

     For more information please contact:

    Nikos Kyriakou (, Inorganic Membranes, Meander 236B

    Marie-Alix Pizzoccaro (, Inorganic Membranes, Meander 348

    Louis Winnubst (, Inorganic Membranes, Meander 348

     [1] T. Nakato, J. Kawamata, S. Takagi, Inorganic nanosheets and nanosheet-based materials: Fundamentals and applications of two-dimensional systems, Nanostructure Science and Technology, Springer Japan, 2017.

    [2] Hongwei Fan, Jiahui Gu, Hong Meng, Alexander Knebel, and Jürgen Caro, High-Flux Membranes Based on the Covalent Organic Framework COF-LZU1 for Selective Dye Separation by Nanofiltration Angew.Chem. Int.Ed. 2018, 57,4083 –4087.

    [3] Gang Li, Kai Zhang, and Toshinori Tsuru, ACS Appl. Mater. Interfaces 2017, 9, 8433−8436.

  • Hybrid nanofiltration membrane fabrication and optimization on a pre-functionalized macroporous ceramic support (MSc assignment)

    Many industrial process streams are comprised of solvents and small organic solutes (< 1000 g mol-1). To concentrate these solutes and purify the solvent medium, nanofiltration membranes are employed. The aim of this project is to make a stable and ultra-thin solvent resistant nanofiltration membrane by using a pre-functionalized macroporous ceramic support to direct the organic network formation. This new class of hybrid membranes will have the advantages over traditional membranes due to their ability to withstand basic/acidic conditions, organic solvents, high temperatures etc.

    The candidate will benefit of the expertise and equipment of the Inorganic Membranes group to:

    1.  Fabricate a selective layer on a commercial ceramic support. This method implies the functionalization of the inorganic surfaces via an inorganic-organic linking agent [1], followed by a network formation on the pre-functionalized support [2]. The fabrication process is shown in Figure 1.
    2. Characterization of the as-prepared membranes by various techniques, such as FTIR, AFM, permporometry, electron microscopy, etc.
    3. Synthesis optimization (monomer concentration, linker density, solvents, etc...) to control membrane properties.
    4. Evaluate the performance of membranes under OSN conditions: filtration of both polar and non-polar organic solvents with model solutes

     Figure 1. Schematic representation of the synthesis of a polymeric ultra-thin membrane using a pre-functionalized porous ceramic support.

    Skills which will be developed during this Master assignment which focus on synthesis and characterization:

    • Functionalization of inorganic surface with inorganic-organic linking chemistry
    • Adaptation to state-of-the-art “Click Chemistry” reactions for utilization in membrane technology
    • Characterization of the as-prepared membranes (SEM, EDX, FTIR, AFM, permporometry etc...)
    • Evaluation of membrane performances under OSN conditions (mixtures of solvents and solutes)

    For more information please contact:

    Nikos Kyriakou (, Inorganic Membranes, Meander 236B

    Marie-Alix Pizzoccaro (, Inorganic Membranes, Meander 348

    Louis Winnubst (, Inorganic Membranes, Meander 348

     [1] A.F.M. Pinheiro, D. Hoogendoorn, A. Nijmeijer, L. Winnubst, Development of a PDMS-grafted alumina membrane and its evaluation as solvent resistant nanofiltration membrane, J. Memb. Sci. 463 (2014) 24–32. doi:10.1016/j.memsci.2014.03.050.

    [2] M.F. Jimenez Solomon, Y. Bhole, A.G. Livingston, High flux hydrophobic membranes for organic solvent nanofiltration (OSN)-Interfacial polymerization, surface modification and solvent activation, J. Memb. Sci. 434 (2013) 193–203. doi:10.1016/j.memsci.2013.01.055.

  • Sieving of hot gases by thin film composite membranes (MSc assignment)

    Project outline:

    Global warming due to greenhouse gas emissions is one of the worldwide concerns. Among these gases, CO2 has been recognized as the most responsible one. Many efforts have been made to fabricate membranes, which can separate H2 from CO2 in harsh conditions. Recently, IPOSS membranes show breakthrough results for H2/CO2  selectivities at temperatures up to 300°C, which makes them ideal for using them in the pre-combustion capture.

    IPOSS membranes are polyimide membranes which contain POSS (Polyhedral oligomeric silsesquioxane) as the main building block. They are produced by using a two-step procedure: the interfacial polymerization of POSS and anhydride on a ceramic layer (Fig 1.a), followed by thermal imidization (Fig 1.b). The thickness of the produced layer is less than 100 nm [1].

    Figure 1. two-step procedure of producing IPOSS membranes [1]

    Project description:

    This master thesis aims to enhance the performance of IPOSS membranes. To achieve this, Palladium (Pd) nanoparticles can be used. These nanoparticles are only selective toward H2 and using them in the iPOSS membrane will improve the H2 permeability and H2/CO2 selectivity.

    There are different ways to add Pd nanoparticles to the membranes. In this assignment, you will explore these methods and investigate its effect on the performance of the membranes.

    Project outcome:

    This project is a new approach for producing thin film composite (TFC) membranes contain nanomaterials.


    For more information, feel free to contact Farzaneh Radmanesh (f.radmanesh@utwente .nl)


    1.           Raaijmakers, M.J., and N.E. Benes, Current trends in interfacial polymerization chemistry. Progress in polymer science, 2016. 63: p. 86-142.