Vermiculita e seus usos como absorvente de compostos orgânicos

Abstract

Vermiculite, a hydrated alumino-silicate, is already used worldwide, with various applications in agriculture, industry, construction, and various other sectors of the economy. This project aims to develop new areas of application for vermiculite, especially its use as an absorbent/adsorbent of organic compounds, with extreme importance in combating accidental spills of oil and its derivatives on aquatic surfaces. When submitted to high temperatures, approximately 900°C, the water present between the lamellae that make up the vermiculite structure is abruptly transformed into vapor and the vermiculite, which has the property of expansion, increases significantly in volume, increasing, consequently, its capacity to absorb liquids. To enable the absorption/adsorption of organic compounds, the vermiculite must undergo a physical-chemical surface treatment (hydrophobing). In this project, regional oils of andiroba, babaçu (crude and purified), copaiba, castor bean and pequi were used as hydrophobic agents, and removal efficiencies of organic compounds above 90% were obtained in the case of vermiculite hydrophobized with purified andiroba and babaçu oils. The adsorption tests were also performed, using the solvent extraction technique (hexane), in order to reuse the adsorbed oil and the vermiculite bed in new adsorption steps. The results obtained indicate the feasibility of using vermiculite as an absorbent material, with the advantages of playing an important role in mitigating environmental impacts caused by spills of petroleum products, besides promoting the development of the region, through the application of regional inputs, such as essential oils and the mineral itself.