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. 


  • 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  j.d.wendt@utwente.nl.

  • 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

    *a.k.bysani@utwente.nl

    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

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

    Introduction

    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 (m.a.junker@utwente.nl)

    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.

  • 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.

    Contact:

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

    References:

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