Behaviour of PPCP Substances in a Fluvial Aquifer after Infiltration of Treated Wastewater

Abstract

One of the reasons for the still prevailing concerns about the recycling of treated wastewater is the low efficiency of current Waste Water Treatment Plant (WWTP) technologies for removing Pharmaceuticals and Personal Care Products (PPCP) substances, especially pharmaceuticals. The goal of this investigation was to verify the behaviour of these substances after infiltration into the fluvial aquifer. During an experiment, this water (containing 45 PPCP substances) was infiltrated using a 10 m deep well for a period of one month. The whole process of infiltration was intensified by pumping at a well in a distance of 52 m. In the surrounding monitoring wells, 113 PPCP substances were monitored at three-day intervals with a detection limit in the order of tens of ng/L. The results showed that 32 PPCP substances were already present in the fluvial aquifer before the start of the infiltration experiment and thus represent “background” values. These substances are the result of river water seepage. The influence of infiltration was manifested by changes in the chemistry of the monitoring wells 8–12 days after the beginning of the experiment. The experiment demonstrated the high natural attenuation capacity of the fluvial aquifer, which eliminated a wide range of PPCP substances to a level below the detection limit.