General formulation of characteristic time for persistent chemicals in a multimedia environment
- Univ. of California, Berkeley, CA (United States)
- Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering
A simple yet representative method for determining the characteristic time a persistent organic pollutant remains in a multimedia environment is presented. The characteristic time is an important attribute for assessing long-term health and ecological impacts of a chemical. Calculating the characteristic time requires information on decay rates in multiple environmental media as well as the proportion of mass in each environmental medium. The authors explore the premise that using a steady-state distribution of the mass in the environment provides a means to calculate a representative estimate of the characteristic time while maintaining a simple formulation. Calculating the steady-state mass distribution incorporates the effect of advective transport and nonequilibrium effects resulting from the source terms. Using several chemicals, they calculate and compare the characteristic time in a representative multimedia environment for dynamic, steady-state, and equilibrium multimedia models, and also for a single medium model. They demonstrate that formulating the characteristic time based on the steady-state mass distribution in the environment closely approximates the dynamic characteristic time for a range of chemicals and thus can be used in decisions regarding chemical use in the environment.
- OSTI ID:
- 323816
- Journal Information:
- Environmental Science and Technology, Vol. 33, Issue 3; Other Information: PBD: 1 Feb 1999
- Country of Publication:
- United States
- Language:
- English
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