Infuence of Selected Pharmaceuticals on Biogas Production in Mesophilic Anaerobic Fermentation

This article deals with pharmaceutical compounds as micropollutants in anaerobic digestion of sludge from waste water treatment plant (WWTP). Part of the work included the research into presence of pharmaceuticals in different types of waters. Description of anaerobic fermentation process is also important in terms of optimal conditions. The practical aim of the investigation was preparation of a model of anaerobic fermentation of sewage sludge, where influence of pharmaceuticals on mesophilic anaerobic digestion was monitored. Wash out of micropollutants from sludge in big semicontinuous anaerobic reactors was running since October 2013. The resulting non-adapted sludge from mesophilic reactor was used since March 2014 for pharmaceuticals tests in half-a-litre glass bottles with a septum cap. The compounds of interest were diclofenac, tramadol, ibuprofen, carbamazepine and amoxicillin and their concentration in the tested sludge was 10 μg/L and 500 μg/L. The results showed that pharmaceuticals have different influence on the amount of produced biogas even if they are from the same therapeutic group. In the low concentration, the inhibition was present for diclofenac, carbamazepine and amoxicillin, at the high concentration, while diclofenac showed almost no influence. Other compounds caused a stimulative effect on the process. The mixture of all pharmaceuticals of interest in low concentration was stimulative at first, while it was inhibotory since mid-time of the test.