Estudio para la determinación cinética de adsorción de Arsénico sobre residuos de cacao

Abstract

The objective of this curricular integration work was to study the determination of kinetic parameters of arsenic adsorption on cocoa residues (Theobroma cacao). Cacao fruits from the national variety known as "cacao arriba" were purchased from the Lago Agrio canton, which were divided into two equal parts to be used as a bio sorbent for arsenic dissolved in water. A comparative research was carried out between the two groups of cocoa fruits, the first group was called normal biomass, going through the following processes: cleaning, extraction of seeds and drying; As for the second group called activated biomass, it underwent the following processes: cleaning, seed extraction, drying and activation with phosphoric acid. Subsequently, the physicochemical and morphological parameters of the two biomass groups were evaluated and arsenic adsorption tests were carried out on the adsorbent material with different concentrations of the mentioned pollutant. To compare the adsorption capacity and its kinetics, several mass absorption spectrometry analyzes were performed, which were evaluated with the methods proposed by Freundlich and Langmuir. As a result of the analyzes, it was found that the normal biomass adsorbed 40% of arsenic compared to 25% of the same pollutant adsorbed by the activated biomass, all this, due to the morphology and composition of the normal biomass that exceeds the activated biomass, in addition, it was found that the kinetic model that describes this adsorption process is the one proposed by Langmuir. It is concluded that normal biomass has better characteristics than activated biomass for the adsorption of arsenic in water and it is recommended to evaluate the capacity of cocoa residues in the adsorption of other pollutants.