Evaluation of micropollutant removal from artificially recharged water using activated carbon

Pilot scale micropollutant removal onto three types of granular activated carbon was tested over a period of 25 months. The columns were operated in a mode as similar as possible to the functioning of the main waterworks with the emphasis on minimizing the washing of the activated carbon layers. Sampling was performed monthly and a total of 222 micropollutants were evaluated. The columns were located at a waterworks in central Bohemia (Czech Republic). Real influent water from the river Jizera after artificial recharge and sand filtration was used. The aim of this study was to verify whether the process of micropollutant removal was suitable under the operating conditions at the waterworks. Clear seasonal patterns of micropollutant concentrations in the influent were detected. All three columns were able to effectively remove or substantially decrease the concentration of most micropollutants. The best performance was shown for the activated carbon Aquasorb 5005, which had the highest surface area and a well developed porous structure with the highest proportion of mesopores. The data were evaluated in order to identify micropollutant parameters important for their removal, and the pH-dependent octanol/water partition coefficient was identified as the key parameter. Other important parameters were charge and polar surface area of the micropollutant molecules.