Organic compounds, sorption

Empirically, we sometimes find that nonionic organic compound sorption on inorganic solids is best described with linear isotherms. Such is the case for observations of pyrene sorption on kaolinite suspensions (Fig. 11.6a Backhus, 1990). Generally,... 

Note that such a conceptualization still requires a corresponding desorption of some number, n, of water molecules from the vicinal region to make a cavity near the solid surface in which i must fit. This solvent desorption process contributes an additional free energy term to the overall organic compound sorption process due to breaking of watenwater interactions in this layer. 

Figure 11.7 Apolar and slightly monopolar organic compound sorption coefficients, K,min (L nr2), observed for exchange between aluminum oxides and aqueous solutions plotted as a function of sor-bate hydrophobicity (as measured by yw) apolar series of chlorobenzenes (squares, Schwarzenbach and Westall, 1981) and aromatic and chloroaromatic compounds (diamonds, Maderet al., 1997).

Consequently, it appears that the L/D ratio of PLA influences the gas permeability but no conclusion can be reached regarding the water vapour transport in this pol)uner. Moreover, generally speaking, the crystallization of the PLA matrix makes it possible to decrease the gas permeability and the organic compound sorption in PLA. However, no agreement has been formed regarding the influence of crystallinity degree on water vapour transport in PLA due to the variety of PLA composition (L-lactic acid content) and measurement systems. 

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). 

Ilic, M. R., Jovanic, P. B., Radosevic, P. B. and Rajakovic, L. V., Sorption of hydrogen cyanide onto activated carbon cloth impregnated with metallo-organic compounds, Sep. Sci. Technol., 1995, 30(13), 2707 2729. 

Stauffer TB, MacIntyre WG. 1986. Sorption of low-polarity organic compounds on oxide minerals and aquifer material. Environ Toxicol Chem 5 949-955. 

D. L. Jones and P. R. Darrah, Re-sorption of organic compounds by roots of Zea mays L. and its consequences in the rhizosphere I. Re-sorption of C labelled glucose, mannose and citric acid, Plant and Soil 143 259 (1992). 

There is more current literature which speaks to exactly this point. Hassett -0 has found that the sorption of organic compounds from water to suspended particles is altered in the presence of dissolved organic carbon. Griffin Chian - - and Diachenko have found that the volatility of organic compounds in water decreases when humic materials are present. Perdue -2 has found that the rate of hydrolysis of the octyl ester of 2,4-D is decreased in the presence of humic materials. 

Matter with Sorption Capacity for Hydrophobic Organic Compounds.125... 

In 1968, researchers discovered that a moderate amount of SOM had a pronounced influence on the sorption of organic compounds, unless SOM content is very low (Lambert 1968). Due to the high affinity, the interaction of SOM with HOCs may be described by the following equation ... 

Grathwohl (1990) found a relationship between sorption capacity and the the atomic H/O ratio of NOM. Similarly, there is a good relationship between log Koc and the polarity index (PI) of SOM, defined as the (0+N)/C ratio (DePaolis and Kukkonen 1997 Rutherford et al. 1992 Xing 1997 Xing et al. 1994a). The effect of SOM polarity on sorption of organic compounds is consistent with the well-known theory of solvent polarity on solute solubility. In studying the influence of SOM composition... 

Boyd S, Jin X, Lee J (1990) Sorption of nonionic organic-compounds by com residues from a no-tillage field. J Environ Qual 19 734-738... 

Boyd SA, Mortland MM, Chiou CT (1988a) Sorption characteristics of organic compounds on hexadecyltrimethylammonium-smectite. Soil Sci Soc Am J 52 652-657... 

Carrizosa MJ, Hermosin MC, Koskinen WC, Cornejo J (2004) Interactions of two sulfonylurea herbicides with organoclays. Clays Clay Miner 52 643-649 Celis R, Hermosin MC, Cornejo J (2000) Heavy metal adsorption by functionalized clays. Environ Sci Technol 34 4593-4599 Chappell MA, Laird DA, Thompson ML, Li H, Teppen BJ, Johnston CT, Boyd SA (2005) Influence of smectite hydration and swelling on atrazine sorption behavior. Environ. Sci Technol 39 3150-3156 Chiou CT (1989) Theoretical considerations of the partition uptake of nonionic organic compounds by soil organic matter. In Sawhney BL, Brown K (eds) Reactions and movement of organic chemicals in soils. Soil Science Society of America, Madison, WI, pp 1-29... 

Zhao H, Jaynes WF, Vance GF (1996) Sorption of the ionizable organic compound, dicamba (3,6-dichloro-2-methoxy benzoic acid), by organoclays. Chemosphere 33 2089-2100... 

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