Fig. 8. Photographs for clean up of diesel oil from water and oil/water separation. Water droplets (dyed with blue ink) and diesel droplets (dyed with red oil) of (a) raw cotton and (b) modified cotton. (c) Diesel oil floating on the water surface, (d) raw cotton sunken in water and oil was adsorbed by modified cotton. (e) and (f) A vortex-stirring process was used to absorb the diesel oil using modified cotton. (g) and (h) An oil/water mixture was separated by modified cotton.