NATURAL SORBENTS IN OIL-SPILL CLEANUP

Milkweed (Asclepias) fiber and cotton fiber sorbed significantly higher amounts of crude oil than polypropylene fiber and polypropylene web from the surface of an artificial sea water bath containing crude oil and from a crude oil bath. Milkweed sorbed approximately 40 g of crude oil/g of fiber at room temperature. The soil sorption capacity of kenaf core material was comparable with that of polypropylene web with high-viscosity Bunker C oil. Only a slight variation was observed in the oil sorption of the natural fiber sorbent by Soxhlet extraction and water-soaking treatments before the sorption process. However, alkali-scouring treatment significantly reduced the oil sorption capacity of milkweed and cotton fiber. It was shown that with the aid of suitable mechanical retrieval equipment, sorbed crude oil can be recovered from milkweed and cotton so the sorbents can be recycled several times for oil spill cleanup. The results suggested that a total or partial substitution of commercial synthetic oil sorbents by natural sorbent materials could be beneficial in the oil spill cleanup operation by improving the efficiency of oil sorption and by incorporating other advantages such as biodegradability.