On the Decrease in Reaeration Coefficient Due to Covering of Water Surface with Oil

Abstract

The purpose of this research is to elucidate the effects of oil pollution upon the reaeration phenomena in the seas. The reaeration rate of pure water and that of water whose surface being covered with oil were investigated. Experiments were carried out in the temperature range from 6° to 40.5°C, and A-type petroleum was used as a covering material.
The experimental results are as follows: 1) The reaeration coefficient, k₂, is aff ected by the presence of oil slicks and decreases approximately by 20-40% on water without oil slicks.2) The temperature coefficient, θ, is 1.0 41 in the presence of oil slicks, while it is 1.0 28without them.3) In the experimental temperature range, the equilibrium concentration of dissolved oxygen maximally changes with the amount of oil slicks within a limit of ±10%. The above concentration becomes lower at 6°C and higher at 18.5, 30 or 40.5°C than that in the case of pure water.