Factors influencing the infiltration of pharmaceuticals through soils

Pharmaceuticals and personal care products (PPCPs) are emerging environmental contaminants but studies of their environmental fate have focused on their behaviour during wastewater treatment processes. Little is known about the behaviour of PPCPs in soils and this is important to provide an understanding of how these compounds will be distributed during the infiltration processes which occur both naturally and under a number of treatment procedures. In this study four PPCP compounds (bezafibrate, carbamazepine, chloramphenicol and diclofenac) have been selected for investigation to determine their mobility and leaching behaviour in two types of soils. Under experimental conditions, chloramphenicol showed the highest potential to leach through the soils followed by carbamazepine, bezafibrate and diclofenac, which mirrors the order of their increasing organic carbon adsorption coefficients (Koc). The results suggest that ionic strength, pH and soil organic matter (SOM) are notable factors affecting the sorption and therefore the overall fate of pharmaceutical compounds in the soil environment