الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Oil spill accidents have terrible economic and environmental consequences resulting in the loss of the product and the impact on marine shore and organisms. Among the prevailing recovery techniques, the mechanical recovery technique with oleophilic skimmers is the best and least risky to the environment. The primary objective of this research was to study the effect of modified skimming surfaces on the oil recovery rate (ORR). Four surface types were examined in this study, namely, smooth steel surface, dimpled steel surface, nano-ceramics coated steel surface and sponge-covered steel surface. Many tests were conducted under different operating parameters (oil type, rotational speed, slick thickness, drum dimensions, scraper shape, temperature, and centre height) to assess the performance of the modifiedsurface drum skimmer in the recovery process. Tests were conducted on a model which was integrated with four drums: 1) a smooth surface drum with diameter (d) = 300 mm & length (l) = 200 mm, 2) a dimpled-surface drum with d = 300 mm & l = 200 mm, 3) a smooth surface drum with d = 200 mm & l = 300 mm, and 4) a smooth surface drum with d = 200 mm & l = 455 mm. The results indicated the superiority of the nano-ceramics coated surface over the traditional steel surface in ORR. The nano-ceramics coating was found to catch a minimal amount of water during the recovery process especially with low-viscosity oils. Increase in ORR up to 40%, 34% and 22% were obtained when implementing nano-ceramics coated, sponge-covered and dimpled surfaces, respectively, compared with the smooth steel surface. This was attributed to the structure of the modified surfaces that affected the oil contact angle and the wettability consequently. Modifying the shape of the scraper to flank the sides of the drum increased the recovery rate up to 20% with nano-ceramics coated steel and 23.5% with steel surfaces. Furthermore, an increase in ORR of 73.6% was achieved when increasing the oil slick thickness from 10 mm to 40 mm, with the pure steel surface. A noticeable role was played by oil viscosity in determining ORR since the results indicated an increase of up to 47% when skimming a heavy oil instead of a light oil. Besides, heavy oil ORR decreased by 32% when the ambient temperature decreased by around 15 degrees centigrade. A more pronounced effect was noticed for the drum length as compared with its diameter. Finally, an empirical equation was derived for predicting ORR for steel surface under different operating conditions.