Removal of pharmaceutical residues at Nolhaga wastewater treatment plant

For several years, the Swedish Environmental Protection Agency has given financial support for projects with the aim to improve the aquatic environment, which include investments for removal of pharmaceutical residues at wastewater treatment plants. With this support, Alingsås municipality carried out pilot trials at Nolhaga wastewater treatment plant in 2021, where two treatment lines were investigated; ozonation combined with granulated activated carbon filters (GAC), and biological carbon filtration (BAC).

We spoke with Staffan Kaltin, project manager in Alingsås municipality, who chose to supplement the chemical analysis with effect-based analysis when evaluating the removal efficiency for pharmaceutical residues with different treatment techniques.

“The evaluation with effect-based methods was the most interesting part of the whole project!”

Staffan Kaltin, Project Manager at Alingsås Kommun.

Why did you want to complement the evaluation of your pilot trials with effect-based analysis?
We did not want to limit ourselves to chemical analyzes of individual substances, or to only pharmaceuticals – there are many other harmful substances that can occur and that are affected by the treatment. Therefore, we wanted to use effect-based analysis to get a more comprehensive picture of the treatment efficiency, especially since concentrations of individual substances do not reflect mixture effects, so-called cocktail effects, which effect-based analyses do.


How has effect-based analysis contributed to your project?
Through effect-based analysis, we have gained a more holistic view of the treatment efficiency with the two investigated process alternatives and an understanding of the toxicity of the purified wastewater, which cannot be obtained from concentrations of individual substances. This is particularly valuable from a recipient perspective as we want to ensure that the wastewater is treated sufficiently so as not to adversely affect the recipient.

Staffan Kaltin, projektledare Alingsås Kommun

Photo – Staffan Kaltin.