One of the most efficient means for the removal of spilled oil from either land or sea is the use of sorbent. Date Palm Fibers (DPF) is a natural sorbent that exhibits good sorption characteristics although the relationship between fiber age and oil absorption has not been reported. Oil spill remediation process is presented and mechanism and selectivity of sorption was discussed.
Oil spill simulation was carried out by placing 40 gm crude oil on surface of about 800 mL water at 1000 mL beaker. The removal of crude oil from water by 1 gm raw DPF as sorbent was investigated by batch sorption after varying contact times (5-120 min), oil film thickness (7-47 mm) and the use of two different age fibers (old and fresh fibers) at 5 min drainage time. Gas chromatography study of oil involved in the sorption process was done to determined the molecules sorbed by DPF sorbent. Scanning Electron Microscopy analysis for DPF was also take place.
OSC of the two DPF sorbent increased with increasing contact times being 4.53 gm• oil/gm• sorbent for 5 min contact time while for fresh fiber was 6.286 gm• oil/gm• sorbent. The sorption rate was very fast for both sorbents. At 2 min sorption times we get 4.963 and 6.737 gm. oil/gm. sorbent for the aged and fresh fibers respectively at 2 min draining time. The results show that fresh fibers sorbed more oil than old fibers. This is attributed to the new fibers having a lower crystalline structure than the old fibers. The fresh fibers have more cavities and hollows than the old one as shown by Scanning Electron Microscopy, in which cross sectional images show multi lumens and the side images has a rough surface with large size cavities. Analysis of sorbed oils by new DPF with gas chromatography after four successive sorptions of the same crude oil at sorption time of 30 min to identify the oil components sorbed. The results showed that C2-C4 compounds were completely sorbed by DPF during the four sorptions process using 1 gm. each, e.g. total 4 gm. After 4 sorption cycles, only 4.80% of pentane remained while C6-C8 compounds were reduced by 63.70%.
This works showed that the DPF have a good performance as low cost, biodegradable and environmental friendly sorbent for the removal of oil from water with excellent selectivity toward small molecules compounds. The fresh fiber prove to be superior sorbent for crude oil over the old one. Since PDF are naturally weaved and rectangular mesh net of about 30×40 cm2 area, it will have high sorption efficiency and easily removed from spill site.