Background - Leading developments and innovations with methods for biopolymer
(polyhydroxyalkanoate or PHA) production and recovery, using wastewater and organic residuals
as carbon sources, are undertaken within the Wetsus theme Biopolymers from Water. This theme
bridges science and engineering in bioprocess and materials. It is with potential for meaningful
downstream societal contributions and industrial opportunities from biopolymers produced and
recovered as a part of water quality engineering services. The Dutch Water Authorities act on
goals of renewable resource cycles (Routekaart Afvalwaterketen tot 2030), wherein energy,
mineral, and biopolymer products are to be parallel value-added outcomes to the principal task of
environmental protection from treating municipal effluents. This research project will be to
contribute with innovations in fundamental details of bioprocess in anticipation and cooperation
within ongoing steps to scale up and integrate industrial scale PHA production from municipal
waste. Research questions will relate to key factors that ultimately stand to have significant
bearing on the success of scaled up process through anticipated influences on production
productivity, economy, and polymer quality (value).
Research challenges - PHA production at industrial scale requires skills and technique in fed-
batch bioprocess, and its control. A sufficient mass of VFA rich substrate must be supplied in the
right way to a mass of polymer accumulating activated sludge. Principles of process need to
manage the polymer quality with respect to co-polymer composition and molecular weight
distributions, and mitigate flanking microbial population activity and growth, while maintaining
optimal overall metrics of the economics in productivity. Innovative industrial scale bioprocess
methods, based on exploiting fundamental principles of biomass dynamic response and polymer
storage kinetics, are required for a successful robust upscaled design. These details are novel to
the industry, and they will be essential in anticipation of successful industrial scale facilities. This
project is also about fundamental innovations that can come from connecting a spectrum of ideas
and principles together, and it is directed with purpose towards the real-life goal for the Dutch water
authorities to successfully scale up technology for PHA from Dutch regional municipal wastewater
Objectives and methodology - The research is interdisciplinary, involving applied microbiology,
process monitoring and control, and polymer science. The project will apply practical bioprocess
experimental work at laboratory and pilot scales, alongside modelling and applying theory and
observations, of biomass response, monitoring and control, towards effective advanced process
solutions. The objectives are to:
with municipal surplus activated sludge using volatile fatty acid (VFA) rich streams coming from
acidogenic fermentation of municipal primary sludge.
activated sludge while mitigating growth of other bacteria that would reduce productivity.
biological production, but also through post accumulation, and recovery/purification steps.
direct link to the demonstration plant activities of a demonstration scale project, which will be
underway in parallel during the PhD project.
Students’ requirements: The candidate is a self-driven bioprocess and/or chemical engineer
(MSc degree) who takes own initiatives and can also blend in team collaborative R&D. An aptitude
for practical experimental work at laboratory and pilot scales is essential, as well as skills and
passion for data analysis, programming, and modelling.
Keywords - polyhydroxyalkanoates, bioprocess engineering and control, renewable resources
Academic supervisors: Prof. Robbert Kleerebezem and Prof. Mark van Loosdrecht
(Environmental Biotechnology, TU Delft)
Wetsus supervisor: Dr. Alan Werker (Theme coordinator Biopolymers from water)
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/
|Title||PhD project - Production of PHA from municipal primary sludge VFAs in support of upscaling of PHA production from municipal surplus activated sludge|
|Job location||Oostergoweg 9, 8911 MA Leeuwarden|
|Published||September 6, 2021|
|Application deadline||October 29, 2021|
|Job types||PhD  |
|Fields||Chemical Engineering  |