Needlepunched cotton nonwovens and other natural fibers as oil cleanup sorbents

This study investigates a partial or complete replacement of synthetic sorbents by various biodegradable, natural sorbent materials. The sorbents examined are cotton, milkweed, kapok, wool, and kenaf fibers. It was found that (with the exception of kenaf) the oil sorption capacities of these natural sorbents (as loose fiber forms) were much greater than that of polypropylene. Nonwoven pads were prepared using cotton and polypropylene fibers and their oil sorption capacities were compared. The results indicate that for light crude oil, the oil sorption capacities of the needlepunched cotton-containing sorbents were slightly greater than those of sorbents made of 100% polypropylene fibers. Individual bundles of both cotton and polypropylene fibers gave greater oil sorption than did the needlepunched nonwoven fabrics prepared from the respective fibers. In addition, sorption decreased as needling density increased. Analyses of sorption mechanisms using an environmental scanning electron microscope were also carried out for each fiber.