Project title: Hybrid US/SCWO system for the combined removal of PFAS and sludge disintegration (WP1)
Host Institution: KU Leuven
Supervisor: Raf Dewil (PhD promoter); Co-supervisors: William Peveler (University of Glasgow)
Objectives: to develop a hybrid process comprising ultrasound-assisted supercritical water oxidation (US-SCWO) for the treatment of sludge resulting in (i) a complete mineralization of the organic matter, energy recovery as heat and electricity, (ii) recovery of heavy metals by solubilizing them to the liquid phase and (iii) the full degradation of recalcitrant organic pollutants (with focus on PFAS).
DC1 will assess the use of O2 as added oxidative species in SCWO (<250°C) and compare it to the typical H2O2-addition. DC1 will evaluate the technique for different sludges applying sets of batch experiments. DC1 will apply a design of experiments to support the experimental plan, using metal recovery efficiency and degradation of PFAS (PFNA, PFOA) as output parameters and temperature, pressure, oxidant type and concentration as input parameters. DC1 will define optimised process conditions and link them to the sludge composition and consistency, hereby building a multivariate statistical model. Starting from these results, DC1 will evaluate ultrasound (US) to pre-crack the macromolecular sludge structures and to induce the catalytic activity of indigenous iron on SCWO performance and its influence on the optimum process conditions. DC1 will develop a kinetic model to assess the mechanisms taking place. DC1 will carry out a full energetic evaluation.
Expected results: An optimised hybrid process for metal recovery and PFAS degradation from sludge comprising of US and SCWO. Insights in the kinetics and influential parameters of SCWO of sludge.
Enrolment in Doctoral degree(s): KU LEUVEN Arenberg Doctoral School of Science, Engineering and Technology (BE)