Oil sorption behavior of various sorbents studied by sorption capacity measurement and environmental scanning electron microscopy

Abstract

Oil sorption capacities of various natural and man-made fibrous sorbents were compared in a simulated seawater bath containing oil. Natural sorbents such as milkweed, kapok, cotton, and wool showed higher sorption capacities than man-made sorbents such as polyester, polypropylene, viscose rayon, nylon 6, nylon 66, and acetate. Sorption capacities of the natural sorbents were over 30 g oil/g fiber. No definite advantages were observed using man-made bicomponent and biconstituent fibers over regular man-made fibers with respect to their sorption capacity. Analyses of sorption mechanisms using an environmental scanning electron microscope revealed that an oil deposit disappeared from the fiber surface after a certain time interval in milkweed, kapok, and cotton. This suggested that the sorption of oil in these fibers occurred through capillary action, probably due to their hollow lumens. Contrarily, adsorption, a surface phenomenon, would be the most prominent mechanism for oil sorption of wool fibers due to large amounts of surface wax, irregular scaly surfaces, and crimp. Effects of both adsorption and absorption were shown in the oil sorption of man-made fibers, depending upon the type and shape of the sorbent. Dumbbell-like oil deposits were seen on the fiber surface in certain oleophilic man-made fibers, because of a partial wetting of oil on the fiber surface. For some hydrophilic man-made fibers such as polyvinylalcohol and copolymer of isobutylene-maleic anhydride, the physical configuration of the fiber was a decisive factor in determining oil sorpton capacity of the sorbents.

Impregnation of polyurethane foam with activated carbon for enhancing oil removal from water

“…The presence of the AC particles increases the roughness of surface which in turn helps the foam to hold the adsorbed oil as the physical configuration of the sorbent is an important property for adsorption and capillary action. The same phenomenon about the surface roughness was reported by (Choi and Moreau 1993) and (Radetic et al 2003) in the case of polymeric sorbents such as polyester and recycled wool-based nonwoven material, respectively, especially in oil-rich environment.…”

Acetylation of corn silk and its application for oil sorption

“…The amount and rate of oil which is sorbed into a sorbent are closely related to the chemical property of the sorbent, the molecular arrangement, and the physical configuration of the sorbent such as surface roughness, hollow lumen, porosity, twist, and crimp. Oleophilicity and surface energy of the sorbent are mainly dependent upon the chemical property and the surface wax, which are significant properties in the absorption mechanisms, though the main factor in the adsorption mechanism and capillary action is the physical configuration of the sorbent [20]. FE-SEM images of surface and cross sections of corn silk fiber are showed in Figure 2.…”

“…Viscous oils need longer time to reach the porous interior of sorbents through capillary action. The rate of oil sorption is inversely proportional to the oil viscosity [20].…”

Oil Spill Cleanup from Sea Water by Sorbent Materials

“…Some sorbents that have been widely studied by researchers are milkweed, kapok, cotton fiber [23], polypropylene [24], modified expanded perlite [25], exfoliated graphite [7,26], carbonized fir fibers [27], carbon fiber felts [28], and Sugi Bark Sorbent [29].…”