Reconnaissance Study on Adsorption of Pharmaceuticals and Personal Care Products to Managed Turf Soils and Associated Oxide Nanoparticles

Abstract

The use of greywater or treated wastewater for the irrigation of public greenspaces and athletic fields is becoming a management strategy in water conservation. Water may contain pharmaceuticals and personal care products (PPCPs), as well as oxide nanoparticles (NPs), because these compounds have been detected in sediment-freshwater systems and soils. This study investigated interactions between PPCPs and NPs by batch adsorption experiments using five soil-associated NPs (Fe2O3, MgO, SiO2, Al2O3, and CaO), one common anthropogenic NP (TiO2), fine (<37 μm) fractions of athletic field soils, and seven PPCPs: salicylic acid, propranolol, carbamazepine, bisphenol A, diclofenac, caffeine, and ibuprofen. Results indicated that some sorption can be determined by the net surface charge of the oxide NP or the composite mineralogy of the soil fines, and the overall charge of the attendant PPCPs, over the pH range of the experiments (∼6–8). However, adsorption of several drug–substrate pairs was not explained by net surface charge attraction or repulsion, and data indicated that more-complex adsorption mechanisms are operative in water–soil systems containing the relatively hydrophilic PPCPs investigated.