Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the environment,
which have drawn popular concerns recently. Most studies on the environmental fate of PPCPs have
focused on their behaviors during wastewater treatment processes, in aquatic environments, and in
the sludge, however, little is known about their behavior in agricultural soils. In this study, adsorption
and degradation of six selected PPCPs, including clofibric acid, ibuprofen, naproxen, triclosan, diclofenac
and bisphenol A have been investigated in the laboratory using four US agricultural soils associated with
reclaimed wastewater reuse. Adsorption test using a batch equilibrium method demonstrated that
adsorption of all tested chemicals in soils could be well described with Freundlich equation, and their
adsorption affinity on soil followed the order of triclosan > bisphenol A > clofibric acid > naproxen > diclofenac > ibuprofen. Retardation factor (RF) suggested that ibuprofen had potential to move downward
with percolating water, while triclosan and bisphenol A were readily retarded in soils. Degradation of
selected PPCPs in soils generally followed first-order exponential decay kinetics, with half-lives ranging
from 0.81 to 20.44 d. Degradation of PPCPs in soils appeared to be influenced by the soil organic matter
and clay contents. Sterilization generally decreased the degradation rates, indicating microbial activity
played a significant role in the degradation in soils. The degradation rate constant decreased with increasing initial chemical concentrations in soil, implying that the microbial activity was inhibited with high
chemical loading levels