11.1 Combined removal of antimicrobial resistance and pharmaceuticals from wastewater

This positions has been closed and withdrawn. Applicants are informed about their evaluation.


Antibiotic resistant bacteria are continuously discharged into the environment via effluent due to inefficient treatment of wastewater. The reservoir for antibiotic resistance in the environment therefore grows. Effluent post-treatment can play an important role in reducing the input of antibiotic resistance into the environment. Advanced wastewater treatment techniques have been implemented for the removal of pharmaceuticals in pioneering countries such as Switzerland, with activated carbon and ozone as the most applied ones.
Although antibiotic resistance in the environment is a recognized problem, initiatives for their removal from wastewater are not as far as they are for pharmaceuticals. In the Netherlands, advanced treatment is currently investigated at pilot-scale at several locations, with the goal of removing pharmaceuticals. Within this framework, the discharge of resistant bacteria and genes can be potentially reduced along with the pharmaceuticals, depending on the technology applied. The focus of this research project is therefore, to study the removal of antimicrobial resistance on a pilot scale and to compare it to the removal of pharmaceuticals.

Research challenge
With respect to the contents of the project, the main research challenge consists of comparing the performance of advanced treatment options to remove antimicrobial resistance and micropollutants across different pilot plants, with harmonized detection methods (i.e., removal of culturable resistant bacteria, of resistance genes and of pharmaceuticals). Secondly, this project will study whether bacterial re-growth in treated effluent diminishes the quality of treated effluent. Here, the project aims at studying whether this is related to growth of specific bacterial species, and how far resistant bacteria are present in the re-growing population, using next generation sequencing methods. Last, genetic determinants of resistance can be transmitted between different species of bacteria (“horizontal gene transfer”, HGT), due to conjugation (transfer of genes between two living bacteria) and transformation (uptake of non-cell-bound DNA by living bacteria). Another goal of this project is to investigate whether the genetic material remaining after wastewater treatment can still be involved in HGT processes.

We are looking for an excellent, highly motivated and enthusiastic researcher with an MSc degree in the field of (environmental) microbiology with affinity for water technology/process engineering. Adequate experimental and theoretical skills are required. Candidates with experience in molecular biological techniques are preferred. Knowledge of bioinformatics is a plus. Organisational and communication skills are required in order to facilitate interaction with several external parties.

The research project is part of the Wetsus research theme Source separated sanitation.
The following companies are part of the theme:
- Izore
- desah
- Waterschap Aa en Maas

Promotor: Mark van Loosdrecht (Environmental Biotechnology at TU Delft)
Co- promotor: dr. Heike Schmitt
Wetsus supervisor: dr. Lucia Hernandez Leal

Wetsus, Leeuwarden, The Netherlands

combining scientific excellence with commercial relevance