Organic compounds between

Pollutant Distribution. Of particular importance for the aquatic ecosystem is the distribution of volatile substances, eg, gases and volatile organic compounds, between the atmosphere and water, and the sorption of compounds at soHd surfaces, eg, settling suspended matter, biological particles, sediments, and soils (41,42). 

Pfaffenberger CD, Peoples AJ, Enos HF. 1980. Distribution of volatile halogenated organic compounds between rat blood serum and adipose tissue. Int J Environ Anal Chem 8 55-65. 

Y. Kubota, Ion-Transfer Voltammetry of Organic Compounds at Organic Solvent/Water Interface. Study on Partition of Organic Compounds between Organic Solvent and Water, MS thesis, Fukui Prefectural University, Fukui 1998. 

Collander, R., The partition of organic compounds between higher alcohols and water, Acta Chem. Scand. 5, 774-780 (1951). 

Zinc hydroxy double salts are layered materials similar to layered double hydroxides which show intercrystalline reactivity and incorporate organic compounds between layers.337 Hydroxy double salts of high crystallinity can be obtained by reacting ZnO with organic metal salts in water. Zinc oxide crystals could then be prepared by thermal treatment of hydroxy zinc acetate.338... 

Chiou CT, Porter PE, Schmedding DW (1983) Partition equilibria of nonionic organic compounds between soil organic matter and water. Environ Sci Technol 17 227-231... 

Jafvert, C. T., Westall, J. C., Grieder, E., Schwarzenbach, P. (1990) Distribution of hydrophobic ionogenic organic compounds between octanol and water organic acids. Environ. Sci. Technol. 24, 1795-1803. 

Tolls, J. and McLachlan, M.S. (1994) Partitioning of semivolatile organic compounds between air and Lolium multiflorum (Welsh Rye Grass). Environ. Sci. Technol. 28, 159-166. 

Collander R (1950) The distribution of organic compounds between isobutanol and water. Acta Chem Scand 4 1085-1098. 

Collander, R. The partition of organic compounds between higher alcohols and water, Acta Chem. Scand., 5 774-780,1951. Collett, A.R. and Johnston, J. Solubility relations of isomeric organic compounds. VI. Solubility of the nitroanilines in various liquids, J. Phys. Chem., 30(l) 70-82, 1926. 

Molecular Interactions Determining the Partitioning of Organic Compounds Between Different Phases... 

Figure 3.6 Plot of the natural logarithms of the partition constants at 25°C of a series of apolar, monopolar, and bipolar organic compounds between air and (a) n-hexadecane (n-C H34) and (b) water versus the dispersive vdW- parameter of the compounds defined by Eq. 3-10. Note that from Eq. 3-10 only the compound part is used because the solvent part (1) is the same for all compounds, and that TSA, is in cm2 mol-1.

With these first insights into the molecular interactions that govern the partitioning of organic compounds between different phases in the environment, we are now prepared to tackle some thermodynamic formalisms. We will need these parameters and their interrelationships for quantitative treatments of the various phase transfer processes discussed in the following chapters. 

Give at least 3 reasons why, in environmental organic chemistry, it is so important to understand the equilibrium partitioning behavior of a given organic compound between gaseous, liquid, and solid phases. 

The vapor pressure of a compound is not only a measure of the maximum possible concentration of a compound in the gas phase at a given temperature, but it also provides important quantitative information on the attractive forces among the compound s molecules in the condensed phase. As we will see below, vapor pressure data may also be very useful for predicting equilibrium constants for the partitioning of organic compounds between the gas phase and other liquid or solid phases. Finally, we should note that knowledge of the vapor pressure is required not only to describe equilibrium partitioning between the gas phase and a condensed phase, but also for quantification of the rate of evaporation of a compound from its pure phase or when present in a mixture. 

Furthermore, air-organic solvent partition constants, in particular the air-octanol partition constant, are widely used to evaluate and/or predict the partitioning of organic compounds between air and natural organic phases. Such organic phases are present, for example, in aerosols or soils (Chapters 9 and 11) or as part of biological systems (Chapter 10). 

Has temperature a significant effect on the partitioning of organic compounds between air and a bulk liquid phase How does KM change with increasing temperature ... 

In this chapter we will focus on the equilibrium partitioning of neutral organic compounds between aqueous solutions and water-immiscible, well-defined organic liquids. Our focus will be on situations in which the organic compound is present at a low enough concentration that it does not have a significant impact on the properties of either bulk liquid. 

Finally, it should be pointed out that Part III will add a new important element that we need to describe organic compounds in natural systems, that is, time. So far, we have dealt only with equilibrium concepts (e.g., with the partitioning of organic compounds between different phases), but we have not addressed the question of how fast such equilibria are reached. Thus, in Chapter 12 we will introduce the time axis, that is, we will describe the temporal evolution of a compound concentration due to the influence from various transformation and transport processes. In Part IV we will go one step further and also add space into our considerations. 

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