Selected adsorbent materials for oil-spill cleanup - A thermoanalytical study

Thermogravimetric analysis and differential scanning calorimetry have been applied to determine the adsorption of oil on selected adsorbates: sand, organo-clay and raw cotton. Thermal analysis provides evidence for the interaction and physical adsorption of the diesel oil on the adsorbates. Sand adsorbed diesel to around 33% by mass through weak physical interactions and appeared to fractionate the diesel components. The organo-clays more strongly adsorbed the diesel as evidenced by higher thermal decomposition temperatures. Differential scanning calorimetry (DSC) shows a strong interaction between the organo-clay and the diesel oil. Diesel is effectively adsorbed on organo-clay through adsorption and partitioning and is not removed from the organo-clay until significantly higher temperatures. Cotton displayed a very high adsorption/absorption capacity. A shift in the peak at 110 degrees C (compared with pure diesel at 90 degrees C) suggests an interaction between the diesel compounds and the cotton fibres as diesel is being retained at higher temperatures and more energy is required to evaporate the diesel. DSC was used to determine the strength of the diesel adsorption on the sand, organo-clay and cotton. The use of adsorbent materials to adsorb oil from oil spills is of great significance in modem society. One method of proving the effectiveness of an adsorbent material is through thermoanalytical techniques.