Motivation
The accumulation of pharmaceutical residues and micro-pollutants in wastewater and the environment has become a problem of growing concern. Although some compounds are easily biodegradable, many exhibit a strong refractory character which makes conventional biological wastewater treatment ineffective for their removal. These substances further endanger activated sludge performance and pose a health hazard for both aquatic and terrestrial life.
The application of gas-phase pulsed electrical discharges (plasma technology) is a promising method for the energy-efficient oxidative degradation of aqueous organic pollutants. Reactive oxygen species (ROS, e.g. OH·, HO2, O, 1O2, O3, H2O2) and reactive nitrogen species (RNS, e.g. NO, NO2, HaNbOC) are generated during plasma operation in humid air and at the gas–liquid interface due to direct bombardment of water with energetic electrons, excited states, and ions. Combining an aqueous hyperbolic vortex with plasma has been shown to significantly enhance dissolution and transfer of these reactive species, thereby improving oxidative degradation of priority pollutants.
Recent research at Wetsus has demonstrated the successful realisation and first testing of a hyperbolic vortex plasma reactor. Initial results confirm its effectiveness in degrading pharmaceuticals and PFAS with remarkably low energy requirements. The next step is to optimise this technology for the removal of a wider range of pharmaceuticals under different operating conditions.
Research challenge
The setup is already available and has been tested. The student’s main task will be to conduct further testing and systematic optimisation of the hyperbolic vortex plasma reactor, with a focus on pharmaceutical degradation.
Different plasma/vortex configurations will be assessed in terms of removal efficiency, energy demand, and scalability. This will involve designed experiments exploring tunable physical and chemical parameters, including (but not limited to):
Different plasma/vortex configurations will be assessed in terms of removal efficiency, energy demand, and scalability. This will involve designed experiments exploring tunable physical and chemical parameters, including (but not limited to):
- flow rate, vortex size, and hydrodynamic mixing
- plasma energy density (power, frequency, volumetric flow)
- voltage waveform, electrode number, shape and material
- gas phase composition (air, N2, Ar, or mixtures)
- water chemistry (pH, conductivity, BOD/COD)
- specific pharmaceutical residues as test pollutants
- assessment of degradation products and toxicity assays
Requirements
We are looking for an excellent, highly motivated and enthusiastic researcher with an MSc degree in physics, chemistry, physical chemistry, or related fields, with affinity for water technology/process engineering. Adequate experimental and theoretical skills are required. Candidates with experience in high-voltage / plasma research are preferred. Knowledge of computational fluid dynamics is a plus. Strong organisational and communication skills are expected in order to facilitate interaction with several external partners.
Partnership
The research project is part of the Wetsus research theme Applied Water Physics. The following companies are part of the theme: Biotrack, WLN, Bright Spark, IPF/Grander, Schauberger Natur Technik, Waterschap De Dommel, Thialf innovation lab, Water & light BV
Promotors: Prof.dr.ing. A.J.M. Pemen, TU Eindhoven and Prof. Dr. Jakob Woisetschläger, TU Graz
Co-promotor: Dr. Ir.W.F.L.M. (Wilfred) Hoeben, TU Eindhoven
Wetsus supervisors: Dr. Elmar C. Fuchs, Dr. Luewton L.F. Agostinho
Location: Wetsus, Leeuwarden, The Netherlands
Only applications that are complete, in English, and submitted via the application webpage before the deadline will be considered eligible.
Guidelines for applicants: https://phdpositionswetsus.eu/guide-for-applicants/
