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The octanol/water and air/water partition coefficients have been used to predict chemical's fate in the environment. This study discusses determination and estimation of partition coefficients as environmental parameters using some experimental methods and some thermodynamic models and relations. The new rapid and accurate determination method for air/water partition coefficient was also suggested. Besides environmental ...

The octanol/water and air/water partition coefficients have been used to predict chemical's fate in the environment. This study discusses determination and estimation of partition coefficients as environmental parameters using some experimental methods and some thermodynamic models and relations. The new rapid and accurate determination method for air/water partition coefficient was also suggested. Besides environmental monitoring skill was discussed using the fugacity approach with partition coefficient and thermochemical data, which aimed, to the region of Daejeon. The brief summarization of this work is as follows : 1. In the slow stirring method, saturation time between octanol and water phase was 6 hrs and after injection of organic solute into saturated solution it took at least 13 hrs to arrive equilibrium partitioning between two immiscible phases. The slow stirring method was found as a reliable and reproducing method because the measured K_ow showed good agreements with the literature values. From the experimental results, we found that this method was suitable for measuring of K_ow of hydrophilic compounds in the range of -2＜logK_ow＜3. 2. The generator column method was a convenient and reliable K_ow measuring method. The flow rate of mobile phase was selected as 2-3 ml/min. This method could be used for hydrophobic compounds in the range of 1＜logK_ow. 3. The UNIFAC group contribution method was used to calculate infinitely dilute activity coefficients which is a key factor to estimate K_ow partition coefficient. The following equation was derived for the calculation of K_ow from the infinitely activity coefficient considering solubility of water in octanol.<수식생략> The estimated K_ow values agreed well with the directly measured values, since UNIFAC equation could be a simple and relatively accurate method for calculating K_ow partition coefficients. 4. The K_ow was increased with increase of molar volume. It means that solute will be more partitioned to octanol phase than the water phase. The reason why the chemicals, which have big molar volumes are harmful to human beings. However the organic compounds with substitute were not linear relation with molar volume. 5. Modified EPICS(Equilibrium Partitioning In Closed System) method by using bubble columns reduce the measuring time of K_aw very effectively. The accuracy and reproducibility was better than original EPICS method. The K_aw were also linearly proportional to molar volumes except substituents of benzene, sulfur and nitrogen compounds. 6. The Calculated Henry's constants from the vapor pressure and solubility were agreed relatively well with experimental data, because this calculation method could be used if experimental data was not available. However the accurate estimation and development of this method should be dependent on the accurate thermo-physical data. 7. The application to environmental monitoring of some endocrine disruptors was carried out for specified region of Daejeon city. From the level Ⅲ simulation, the dioxin emitted into air was mostly distributed air and soil. The main transport mechanism of dioxin was deposition from air to soil and water. The PCB emitted into water and air was mostly distributed in sediments. The main transport mechanism of PCB was deposition from water to sediment. The parathion emitted into water and air was mostly distributed in soil. The overall residence time was long. The main transport mechanism of parathion was deposition from air to soil. 8. Fugacity approach model by undertaking Level Ⅲ calculation showed good information about chemical partitioning and its transformation through the reaction and advection process in the environment. The environmental monitoring skill gives a picture of natural behavior of chemicals in the environments and showed quantitative information on environmental fate processes for specific chemicals. If reasonable emission rate of chemicals with validated transport parameters are used, this skill may be applicable to the remedy of an injured organism and monitoring of contaminated environment.

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