Abstract
Experiment to investigate the dispersive effects of underwater dispersant, namely, the reduction of rise velocity of oil droplets and the increase of diffusion area, have been carried out. A beaker test of mixed sample of Marine Diesel Fuel (MDF) and dispersant was carried out and the particle size distribution was measured to confirm the pertinent ratio of dispersant. As the dispersant is a solution of nonionic surfactant and hydrocarbon solvent, the relation between hydrocarbon solvent and MDF was investigated by Gas Chromatography (GC) analysis. The oil concentration in water was confirmed to be linear to the oil dispersant ratio. As the dispersant reacts to water, the mixed sample of MDF and dispersant was discharged from the nozzle installed at the bottom of a water tank 3 m in height. The behavior of this mixed sample was analyzed by high resolution camera. PTV, PIV, and concentration change method were used to analyze the rise velocity and diffusion area of the sample. It turned out that the reduction of rise velocity of oil droplets and the increased diffusion area of the sample were the effect of the dispersants. Furthermore, the rise velocity of oil droplets was estimated from the size of oil particles.
