The Application of Fugacity and Activity to Simulating the Environmental Fate of Organic Contaminants
The concept of fugacity, which is widely used in chemical processing calculations, has also been successfully applied to a variety of environmental simulations of the fate and transport of organic contaminants. The challenges of estimating fugacities in environmental phases are discussed, especially for ill-defined phases such as soils, sediments, and biota for which activity coefficients and molar volumes cannot be measured. It is shown that by lumping these quantities and a reference fugacity in a single parameter, empirical partition coefficient data can be used to deduce fugacities and thus the relative equilibrium status between phases and directions of diffusive transport. For assessments of substances that display narcosis, chemical activities, which can be readily deduced from fugacities, can provide valuable estimates of the proximity of calculated or measured environmental concentrations to potentially toxic levels. Five illustrations are presented to demonstrate the value of applying the fugaci...
In this article we have investigated intermolecular excited-state proton transfer (ESPT) of firefly’s chromophore D-luciferin in DMSO–water binary mixtures using steady-state and time-resolved fluorescence spectroscopy. The unusual behavior of DMSO–water binary mixture as reported by Bagchi ... more
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Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more