First experiences with the use of a pilot-scale combined bioreactor for the removal of pesticides from agricultural runoff

This article deals with a denitrification bioreactor, which is a relatively simple passive device supporting the natural process of denitrification and has been used abroad for many years to remove nitrates from agricultural runoff. In 2023, a pilot bioreactor with a volume of 4.2 m3 filled with poplar chips was launched in Němčice in the South Moravian Region, from which samples are regularly taken and analyzed to determine whether this device can be used not only to reduce the concentration of nitrates, but also pesticide substances. Laboratory tests are being carried out in parallel to verify the effect of selected pesticide substances on the efficiency of denitrification. About 360 pesticide substances were identified in samples from the pilot bioreactor, and their total concentration was reduced by up to 70%. The laboratory tests carried out so far have not demonstrated the effect of pesticide substances on denitrification.