Alternative adsorbents applied to the removal of natural hormones from pig farming effluents and characterization of the biofertilizer.

Pig farming has a very strong economic importance in Brazil. The residues from this activity are applied to the soil because of their excellent characteristics as biofertilizers. The present study aimed at studying the estrone, 17β-estradiol, and estriol natural hormones, emerging contaminants present in this type of residue that are not mentioned in the current legislation. The characterization of the pig farming effluent presented high concentrations of hormones (mg L-1). The objective was to apply the biosorbents to the removal of the hormones in batch systems directly in the manure heaps without affecting the potential of the effluent as a fertilizer. It was verified that the adsorption of hormones using the rice husk biomass in natura and soybean hull in natura, abundant alternative adsorbents, presented a good capacity of removal of hormones. The presence of the organic materials (rice husk and soybean hull) caused few alterations in the biofertilizer characteristics, demonstrating that these adsorbents present a potential of application in batch treatment systems, with possible applications related to pig farming effluents containing natural hormones.