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. 


  • PFAS removal using bio-based sorbents

    In our everyday lives we frequently use products which contain fluorinated chemicals (non-stick cookware, cosmetic products, water resistant clothing, ect.). In order to produce these fluorinated coatings the industry uses poly- or perfluorinated alkyl substances (PFAS) in their processes. Both the waste streams from these production processes and excretion from these products themselves leads to these PFAS entering our water supplies. Many of the problematic molecules in this class of compounds (containing >9000 different compounds) contain a charged head group giving rise to high solubilities in water combined with a very stable carbon-fluorine tail. The strength of the fluorine-carbon bond means that these compounds are non-biodegradable and they will therefore ‘almost’ indefinitely build up inside of the water system. For this reason these compounds are also often referred to as the ‘forever chemicals’.

    In recent years there is increasing concern that the ubiquitous presence of these PFAS in water resources is not addressed by current water treatment facilities and therefore they end up in drinking water. Currently the only widely employed method for removal of PFAS from water is adsorption onto activated carbons [1],  however the use of activated carbons seems to be unsustainable from both a economical perspective and a environmental perspective. In the Netherlands the concern about these compounds has consistently shown up in the news over the past couple of years, although many regions in the USA [2] and China [3] are substantially more severely impacted.

    In this project you will use bio-based materials of different origins and test their ability to adsorb PFAS from water. Both batch testing and flow through testing will be employed to asses adsorption capacity and kinetics at environmentally relevant concentrations. Furthermore you will need to characterise the adsorbents to be able to make a fair comparison. Fitting of adsorption models, statistical analysis and choices in data presentation will be instrumental to make your results both relevant and meaningful. This is a very active field of study, so your view on what practises are correct and which are less relevant is very valued. The assignment is suitable for students of universities (both bachelors and masters level) and students of universities of applied sciences.

    This assignment is part of a project to develop a new process to treat water resources plagued by PFAS to make drinking water that is safe for consumption. The data you collect will be directly used for the future direction of the project!

    If you are interested in this assignment please contact Jurgen Roman (j.b.roman@utwente.nl).

     

    Picture of Set up to be used

    [1] Xiao, X., Ulrich, B. A., Chen, B., & Higgins, C. P. (2017). Sorption of Poly- and Perfluoroalkyl Substances (PFASs) Relevant to Aqueous Film-Forming Foam (AFFF)-Impacted Groundwater by Biochars and Activated Carbon. Environmental Science and Technology, 51(11), 6342–6351. https://doi.org/10.1021/ACS.EST.7B00970

    [2] Johnson, C. D. (2022). Per- and Polyfluoroalkyl Substances: A Preliminary Evaluation of Groundwater Contamination in the Western States. https://www.osti.gov/biblio/1879543

    [3] Liu, L., Qu, Y., Huang, J., & Weber, R. (2021). Per- and polyfluoroalkyl substances (PFASs) in Chinese drinking water: risk assessment and geographical distribution. Environmental Sciences Europe, 33(1), 1–12. https://doi.org/10.1186/s12302-020-00425-3

  • Removal of micro-pollutants from wastewater with a hybrid biological and nanofiltration pilot

    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  j.d.wendt@utwente.nl.

    Pictures: 1,2 = bioreactor, 3 = settler, 4 = nanofiltration


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