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) which contains elevated concentrations of OMPs, and needs to be treated. This project uses a unique pilot system at a scale of 1000 L/hr, with a recycle of the concentrate to a biological wastewater treatment system as depicted in the schematic overview. This biological treatment system is also part of the pilot. You can find pictures of the full installation below as well. In this assignment, you can investigate the total removal of OMPs as well as the general effect of the recirculation of concentrate on the system; what’s the effect of the concentrate on the biological activity and would it be possible to reuse the clean water for other purposes? Furthermore, you can optimize the operation of the membranes by changing the process conditions.
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 include:
- Contributing to applied research by answering relevant research questions.
- Ensuring smooth operation of the pilot plant, observing possible (operational) issues and solving them.
- 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 students of universities and universities of applied sciences, for both internships and graduation assignments.
You will have the opportunity to bring forward 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 firstname.lastname@example.org.
Pictures: 1,2 = bioreactor, 3 = settler, 4 = nanofiltration
- Pressing PECs to Plastics: Exploring polyelectrolyte combinations for ion-exchange applications
Ameya Krishna Bysani1,2,*, Saskia Lindhoud2, Wiebe M. de Vos1
1 Membrane Surface Science, Membrane Science and Technology, Universiteit Twente
2 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
- Sieving of hot gases by thin film composite membranes (MSc assignment)
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 .
Figure 1. two-step procedure of producing IPOSS membranes 
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.
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.