Removal of oil by vermiculite

Studies were carried out to evaluate the sorption capacities of expanded and hydrophobizied vermiculite. Sorption capacity is the weight of oil picked up by unit weight of a sorbent Vermiculite was made hydrophobic by adding carnauba (cerifera) wax. Initial oil pick-up by the sorbents; on pure oil and oil on aqueous medium was evaluated. Batch kinetic studies were conducted to evaluate the saturation speed of expanded and hydrophobized vermiculite on sorption of oil. Expanded vermiculite showed sorption capacities of 2.53g/g, 2.56g/g and 2.62g/g for synthetic mineral oil (SMO), vegetable oil and Kutwell oil, respectively, whereas hydrophobized vermiculite showed 2.46g/g, 2.49g/g and 2.53g/g. In the case of oil on an aqueous medium, hydrophobized vermiculite showed higher sorption capacity than expanded vermiculite. In this case, the sorption capacities of expanded vermiculite were 1.8g/g, 1.91g/g and 2.89g/g for SMO, vegetable oil and Kutwell oil, respectively, whereas those of hydrophobized vermiculite were 3.45g/g, 3.87g/g and 4.08g/g. It was found that oil can be recovered from vermiculite by applying pressure. These studies also showed that vermiculite can be used as a sorbent for oil removal and hydrophobized vermiculite is a better adsorbent for oil floating on water.