Gas Transfer at Water Surfaces



The burning of fossil carbon compounds causes an annual rise of about 0.2% of the total atmospheric CO2, which is about 50% the annual output of manmade CO2. One of the major reasons for this beneficial phenomenon is probably the CO2 uptake by the ocean water. A thorough knowledge of this process is needed for a prediction of the long-term impact of the use of fossil fuels on the environment. The example indicates that mass transfer across the gas-water interface is an important aspect in the geophysical, geochemical, and biochemcial cycle of natural and manmade substances. It regulates the transition between the dissolved state in the water and the gaseous state in the atmosphere. The knowledge of the air-water exchange is probably the most advanced of all the transport processes between environmental compartments. Nevertheless, there is still a need for a better understanding of this interfacial mass transfer, which is a critical factor of great scientific and practical relevance in assessments of the various pathways of wastes in the environment and for their engineering management.