ADSORPTION OF HORMONE 17α-Methyltestosterone IN SOILS

Abstract

With the increase in fish production in fish farming systems, mainly tilapia, the use of the hormone 17α-methyltestosterone (MT) as an inducer of the masculinization of fry has grown together. The probability of contamination of natural resources also tends to increase, and there is no Brazilian law that regulates the content of this hormone in waters. The study of the interaction of the hormone with the typical soil of the producing regions is essential to understand the factors that influence its adsorption. This work used two samples of Eutropherric Red Oxisols and the conditions of the interaction of the hormone in static (resting), and dynamic (agitation) processes were evaluated, using isothermal models. The results showed that the higher organic matter content of the soil and the higher salinity of the aqueous medium increases the adsorption of MT in the soil in the static process. For the dynamic process, the Fe content influences the higher adsorption in soil. The pH of the medium does not affect the adsorption in any of the processes. The adsorption has exothermic characteristics, and the adsorption equilibrium is reached in 24 hours, and the Freundlich model for the soil 1 sample and the Temkin model for the soil 2 sample is the most suitable for the adsorption process. According to parameters calculated for the Dubinin isotherm, soil adsorption tends to have chemical interactions between adsorbent-adsorbate. These results show concern for the amount of adsorbed hormone sediment in fish farming tanks and their release to the water body, with the possibility of contamination of natural resources.