Adsorption of azithromycin in agricultural soils of the Bogotá savanna, Colombia.

Azithromycin is one of the most widely used macrolide antibiotics in medical treatment. However, there is little information on studies of the ecotoxicity, persistence and mobility of this type of compounds in the environment, although their presence in surfaces and wastewater has already been detected (Hernández et al., 2015). Based on this approach, the present research performs an analysis of the behavior of the adsorption process of azithromycin in soils of different textural classes, with the intention of establishing a first approach to assess the destination and transport of such substances in the biosphere. From the results of the evaluation of the conditions of adsorption of azithromycin, it is established that the Langmuir model has a better fit for clay soils with correlation coefficients R2 between 0.998 and 0.961. In contrast, the Freundlich model fits the soil with higher sand fraction with a higher correlation, R2 of 0.9892. Finally, based on a correlation analysis between the clay content, the percentage of organic matter and the adsorption coefficient K, it was evident that the adsorption of azithromycin is mainly related to the inorganic fraction of the soil.