PFAS is used for a very diverse set of applications thanks to its many unique properties. A major drawback of this class of substances is that their inherent high stability makes them very resistant to any type of degradation. PFAS contamination is found in low concentrations in the general water supplies and has been identified in humans. Recent findings have shown that unique bacteria show significant rates of degradation of several PFAS species. The mechanism of degradation is still unclear.
The best way to ensure degradation of PFAS
PFAS is present in a strongly diluted form at many locations rendering chemical methodologies for degradation largely unviable. Although the concentrations are low, PFAS do pose a health risk and therefore should be degraded. It is known that some natural degradation does occur, but the mechanism requires further investigation in order to lower the concentration dependence of the degradation rate and to identify the potential by-products that are formed, so as to achieve complete and fast degradation. In this initiative WFBR takes the lead in unraveling the mechanism and further optimizing PFAS degradation and concentration dependence by employing Adaptive Laboratory Evolution (ALE).
Adaptive Laboratory Evolution allows natural selection of the best enzymes out of billions of permutations
The system used at WFBR will be a system that automatically selects for enzyme mutations that show increased efficacy in conversion of PFAS to CO2 and fluoride salts. Standard PFAS degrading Pseudomonas species will be tested for their ability to degrade various PFAS species after which a strategy for further optimization will be defined. The organisms will be evolved in a system that will be supplied with PFAS compounds as the only carbon source, which induces a coupling of the PFAS degradation rate to growth rate of the organism. This allows for fast selection of the optimal PFAS degrading organism.
The adapted micro-organisms may be employed at specific sites with high PFAS concentrations. This will be done in a fit-for-purpose membrane bioreactor that retains the adapted micro-organisms. The bioreactor ensures a maximum loading and containment of adapted bacteria, so they will not be released from the bioreactor into the environment.
Co-funding industrial partners are invited
The initiative will be submitted to NWO-TKI. As co-funding partners we invite companies in the both the chemical industry as well as suppliers of water treatment technology that are looking for solutions of PFAS contaminated water streams.