Per- and polyfluoroalkyl substances (PFAS) have remained persistent environmental contaminants since the 1950s, despite ongoing efforts to curb their production and find alternatives. Most health studies have focused on Perfluorooctanoic acid (PFOA) and Perfluorooctane sulphonic acid (PFOS), leaving limited data on other PFAS compounds in water. The European Union, particularly the Netherlands, has implemented stringent measures to control PFAS in drinking water due to their uncertain health impacts on
humans. Recently, the Dutch Institute for Public Health and Environment (RIVM) proposed a new guideline of 4.4 ng PFOA equivalent (PEQ) per litre for PFAS in drinking water, a substantial reduction from the current European Drinking Water Directive standards of 100 ng/L for the sum of PFAS and 500 ng/L for total PFAS.

While improving drinking water quality is expected to have positive health outcomes, the advanced treatment technologies required to meet this new guideline can be harsh, potentially releasing emissions that may cause negative health effects. This research, centred on the Leiduin drinking water treatment plant operated by Waternet in the Netherlands, investigates whether the health benefits of the new guideline outweigh the potential harms caused by the treatment processes necessary to achieve it.

To explore this, the study first calculated the Disability-Adjusted Life Years (DALYs) lost due to PFAS exposure from drinking water at the current concentrations, exceeding the 4.4 ng PEQ/L guideline, using a literature review to link guidelines with PFAS health effects. The second step involved conducting a Life Cycle Assessment (LCA) of the treatment system at the Leiduin plant, focusing on the treatment steps necessary to meet the new guideline, and calculating the DALYs lost due to the environmental impact of achieving the 4.4 ng PEQ/L standard. These DALYs were then compared to assess whether adhering to the new guideline is justified in terms of health impacts.

The results indicate that the DALYs associated with the current and proposed guidelines fall within similar ranges, showing limited health benefits. Specifically, the health benefits (in DALYs) gained from implementing the new guideline range from 0.4 to 4 per year, while the DALYs lost due to the treatment technologies required at the Leiduin plant range from 1.55 to 3.25 per year for the population receiving drinking water from the Leiduin site, depending on the type of activated carbon used in the treatment process.

These findings suggest that the potential health benefits of stricter PFAS regulations in drinking water maybe counterbalanced by the negative health impacts of the treatment technologies required to achieve
these lower concentrations

The main research question of this project was:
"How effective is the integration of a foam fractionation system in an activated sludge water treatment plant, on the removal of Per- and Polyfluoroalkyl Substances?"
To determine how foam and activated sludge can have an influence on PFAS removal, a controlled environment was created by building a bench-scale reactor that tries to mimics the full scale activated sludge WWTP of landfill Zeeasterweg. By doing this the effect on the biological performance was tried to be determined. Furthermore, a representative sample of the landfill leachate from the landfill, was used as the influent for the bench scale reactor. This leachate predominant PFAS compounds were: MeFBSAA (13.5 μg/L) and PFBS (8.8 μg/L) accounting for 70 % of total PFAS levels. To answer the main research question, two mass balances for a selected group of target PFAS compounds were develop for two experiments. The fist experiment was focusing on the PFAS removal efficiency without any foam production at all. To achieve this, antifoam was dosed on top of the nitrification zone so that no foam could be produced. The second experiment was called the "Foam Fractionation". In this experiment anfoam fractionation system was added to the nitrification zone of the bench scale reactor. This was done to determine the effect of collecting and removing the foam that was being produced inside the reactor.

Man made emergent contaminants are posing a big treat to the environment and human health. Their accumulation in water resources threatens the ecosystem equilibrium and challenges the current technologies to produce safe drinking water. This research explores anode oxidation (AO) using a Magnéli phase reactive electrochemical membrane (REM) flowthrough reactor as an alternative to treat reverse osmosis concentrate (ROC) water containing a broad list of organic micropollutants (OMPs). ROC water produced in two drinking water treatment facilities in the Netherlands was used to test the technology. This study searches for insights to manage ROC waste containing recalcitrant OMPs and safely discharge effluent to surface water.

Throughout laboratory experimentation, the effectivity of degrading OMPs (per- polyfluoroalkyl substances, pharmaceuticals, corrosion inhibitors, and synthetic dyes) was investigated. Main findings suggest that 100 mg/L Methylene blue (MB) spiked in an artificial water matrix is completely mineralized after an applied charge dosage (CD) of 22.56 kC/L. Additionally, pharmaceuticals spiked in artificial water matrix and ROC were degraded above 80% after applying a charge dosage of 5.64 kC/L. Finally, PFOA and PFOS degradation for drinking water utilities 1 & 2 resulted in an average of 49.5 and 76.90 % respectively after applying 120 kC/L.

Moreover, it was found that hardness in water inhibits the degradation capacity reducing the effective area of the anode with scaling deposition. Besides, the calcium and magnesium content slightly increases the energy consumption and the frequency of chemical cleaning required to maintain the reactor. The Magneli REM reactor has capabilities to degrade OMPs when treating ROC. Operational parameters such as flow rate, and CD can be adjusted to obtain better degradation rates. However, the treated water could contain byproducts with recalcitrant properties and high toxicity (for instance, ultra and, short chain PFAS, bromate, chlorates and perchlorates). For that reason, monitoring and further treatment is recommended to safely discharge back to surface water.