Sorption and desorption of sex hormones in soil- and sediment-water systems: A review

Sex hormones are a group of potent endocrine disruptors that can be released into agricultural soils and sediment via wastewater discharge and manure fertilization. Sorption represents a critical determinant for the transport potential and risks of sex hormones in the environment. Therefore, this study reviewed the sorption and desorption mechanisms of sex hormones in soil- and sediment-water systems, and summarized the effects of various factors on sorption and desorption processes. A total of 359 set of sorption data were collected from the literature. Sex hormones were mostly described by the linear model. The sorption magnitudes (logKoc) of estrogens, androgens, and progestins were in the range of 2.77–3.90, 2.55–4.18, and 2.61–4.39, respectively. The average logKoc values of the sex hormones were significantly correlated with their logKow values (R2= 0.13, p < 0.05), while the R2 values were much lower than those when fewer sex hormones were included for analysis. In addition, the Kd values of most sex hormones were significantly correlated with the OC% of soils and sediment (R2= 0.16–0.99, p < 0.05), but were insignificantly correlated with the particle size distribution and surface area. These results indicated that hydrophobic partitioning interaction and other specific interactions are responsible for sex hormone uptake in soil- and sediment-water systems. The sorption of sex hormones in soil- and sediment-water systems can also be affected by other environmental variables, including pH, temperature, and ionic strength. Future studies should focus on the coupled leaching-sorption processes in manure-water-soil systems under field-scale conditions.