Recycling waste tire powder for the recovery of oil spills

Abstract

Waste tire related environmental problems and its recycling techniques have been a major challenge to society. Current waste tire recycling market is too small to accommodate the tire generated annually. Therefore, it is of crucial importance to develop new markets for waste tires. Tire rubber is flexible and has hydrophobic (oil-philic) characteristics, making it a good candidate as an oil adsorbent. In this paper, the possibility of applying waste tire powder as a sorbent for the recovery of spilled oil was explored. The results indicate that 2.2 g of motor oil can be adsorbed to each gram of 20 mesh tire powder. Due to its elastic property, waste tire powder is re-usable for over 100 times without decreasing its oil absorption efficiency. Therefore, at least 220 g of motor oil can be recovered per gram of waste tire powder, which is very competitive to commercial sorbent. The results of this study indicated that sorption efficiency increased as the tire powder particle size decreased, and decreased as the environmental temperature increases. When applying the waste tire powder to oil slicks on seawater, the oil sorption efficiency is shown to be better than if it was on fresh water. Efforts have been made to enhance the waste tire powder's oil sorption efficiency. Results indicated that the highest efficiency was obtained when the waste tire powder was pre-cleaned by n-hexane, followed by water cleaning > un-cleaned > dishwashing liquid cleaned > seawater cleaned. Compared to a commercial oil sorbent, the result indicated that waste tire powder was economically more feasible, if it was re-used for 100 times. More efforts are encouraged to enhance the waste tire powder's oil sorption capacity without decreasing its re-usable characteristics.