Department Process Engineering
AK24Water - Use of activated carbons (GAC/PAC) in a combined process
Eawag tested various processes for the elimination of micropollutants at the semi-technical and full-scale level at the Glarnerland WWTP over four years between 2017 and 2020 (report).
Following the implementation of granular activated carbon (GAC) filtration (commissioned in mid-2023) and the option of additionally dosing powdered activated carbon (PAC) into the biological treatment, Eawag is now supporting the operation of the processes with a monitoring program and specific individual studies. The Glarnerland wastewater treatment plant is the first plant to combine GAC filtration with pre-dosed PAC in the biological treatment.
The AK24Water project aims to gather and consolidate experience on the operation of GAC filters. Measurements of SAC, MV, and DOC of individual cells during dry weather are used to estimate when the average quality target of 80% MP removal in parallel-operated filter cells at the plant's effluent will fall below the threshold.
To define a final cutoff criterion for the replacement of individual GAC cells, the interaction with the PAC stage will be considered. Based on the identified dependencies in the datasets and time series, strategies will be developed in collaboration with project partners for optimal GAC loading (filter regime), the optimal GAC type, and PAC dosing to mitigate GAC performance losses during wet weather inflows (diluted wastewater matrix).
Another focus is comparing the efficiency of different GAC types used in the two treatment lanes of the wastewater treatment plant."
Publications
Project duration
The project duration is around 3 years. Start January 2024
Financing
Wastewater Association Glarnerland, AVG
Partners
Wastewater Association Glarnerland (AVG), Bilten,
Engineering company HunzikerBetatech AG, Winterthur