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(262) Effect of temperature on environmental partitioning, persistence, and atmospheric transport of semivolatile organic chemicals. Beyer, Andreas1, Matthies, Michael1, Wania, Frank2, Gouin, Todd3, Mackay, Donald3, 1 2 3 ABSTRACT- When assessing the environmental fate of organic chemicals temperature certainly plays an important role, since it affects chemical partitioning properties and degradability as well as environmental processes. If temperature is to be included into environmental fate models one is faced with the problem that temperature dependent physical-chemical properties are available only for a limited number of substances. Vapor pressures, Henry's law constants, octanol-water partition coefficients, and degradation rates as functions of temperature have been compiled for a set of organic chemicals and processed to be consistent with thermodynamic laws. These physical-chemical properties were used to perform simulations of environmental fate in a temperature range from 5 to 30°C. It is discussed how temperature affects the partitioning behaviour and overall persistence. Special emphasis is put on the atmospheric transport of semivolatile organic chemicals. The characteristic travel distance is a descriptor for the susceptibility to long-range transport. Its temperature dependence provides insights into several aspects of environmental fate. The characteristic travel distance can increase or decrease when temperature increases. It is discussed how the chemical's properties determine the temperature dependent change of the characteristic travel distance. The temperature variability of the characteristic travel distance can also serve to assess the likelihood of cold condensation. It is shown how a measure can be derived from the model results that quantifies the cold condensation potential within a certain temperature range. Key words: Long-range transport potential, modelling, temperature, persistent organic pollutants |
