Extracellular polymeric substances internship
Type of project:Ā Ā BSc/MSc Thesis/Internship
Duration:Ā Ā 5-9 months, start from January 2026 or later
Location:Ā Ā Wetsus, European Center of Excellence for Sustainable Water Technology, Leeuwarden, the Netherlands
Salary:Ā Ā The maximum Wetsus allowance for this internship is 425 ā¬ per month. Grant holding students (ie Erasmus or other) receiving financial support of less than 425 ā¬ per month can apply for a top-up supplement to the maximum allowance.
Project Background
Synthetic flocculants such as polyacrylamide are widely used in (waste)water treatment due to their good flocculation capacity. The flocculation capacity of these synthetic flocculants are mainly due to their properties like high molecular weight and charge density. However, these synthetic flocculants derived from fossil fuels result in environmental issues like a high carbon footprint and potential eco-toxicity. Extracellular polymeric substances (EPS), biodegradable microbially-secreted polymers in wastewater treatment processes, have similar properties to synthetic flocculants. Therefore, EPS are considered a green alternative in flocculation.
The flocculation capacity of EPS is influenced by their properties like molecular weight, charge density, and branching degree. However, the kinetics of EPS production is poorly understood, particularly in mixed cultures under nutrient-limited conditions. Understanding the EPS production kinetics in mixed cultures is essential for improving EPS yield and flocculation performance, and for providing key insights into the scale-up from lab-scale reactors to full-scale systems.
The student joining this project will operate bioreactors and investigate the kinetics of EPS production under nutrient-limited conditions, as part of theĀ PhD researchĀ of Bohan Chen. The outcome of this project is expected to promote EPS to outperform synthetic flocculants and contribute to sustainability in (waste)water treatment.
Your task
- Operate three bioreactors under different conditions and prepare feeding solutions for each reactor
- Water quality analysis three times a week
- Extraction and characterization of EPS (protein and polysaccharides concentration, molecular weight, and charge density)
- Test EPS flocculation performance
- Write a final report of this internship
Your profile
- Background in Environmental Engineering/Chemical Engineering/Biotechnology, or related fields;
- Great interest in bioprocesses, wastewater treatment and biopolymers;
- Highly motivated, responsible, and willing to learn about bioreactor operation and flocculation;
- Fluent in English and good English writing skills;
- Experience with bioreactor operation and kinetic modeling in bioprocesses would be considered a plus.
Your benefits
- Knowledge of bioprocess and mathematical kinetics modeling
- Hands-on laboratory experience in various molecular & analytical techniques
- Close guidance via weekly or biweekly meetings
- Experience the multidisciplinary and collaborative environmental research at Wetsus
- Join a large pool of thesis/internship students in an international working environment
- The maximum Wetsus allowance for this internship is ā¬425 per month. Grant holding students (ie Erasmus or other) receiving financial support of less than 425 ā¬ per month can apply for a top-up supplement to the maximum allowance.
How to apply
Please upload two files:
- Your CV (max. 2 pages, A4 page), including a list of core courses
- Motivation letter (max. 1 page, A4 page) (in English)
You can contact Bohan Chen (bohan.chen@wetsus.nl) if you have any questions or need more information.
