Effect on sorption

Many factors affect the mechanisms and kinetics of sorption and transport processes. For instance, differences in the chemical stmcture and properties, ie, ionizahility, solubiUty in water, vapor pressure, and polarity, between pesticides affect their behavior in the environment through effects on sorption and transport processes. Differences in soil properties, ie, pH and percentage of organic carbon and clay contents, and soil conditions, ie, moisture content and landscape position climatic conditions, ie, temperature, precipitation, and radiation and cultural practices, ie, crop and tillage, can all modify the behavior of the pesticide in soils. Persistence of a pesticide in soil is a consequence of a complex interaction of processes. Because the persistence of a pesticide can govern its availabiUty and efficacy for pest control, as weU as its potential for adverse environmental impacts, knowledge of the basic processes is necessary if the benefits of the pesticide ate to be maximized. 

Nzengung VA, Voudrias EA, Nkedi-Kizza P, Wampler JM, Weaver CE (1996) Organic cosolvent effects on sorption equilibrium of hydrophobic chemicals by organoclays. Environ Sci Technol 30 89-96... 

Nzengung, V. A., E. A. Voudrias, and P. Nkedi-Kizza, Organic cosolvent effects on sorption equilibrium of hydrophobic organic chemicals by organoclays , Environ. Sci. Technol., 30, 89-96 (1996). 

Bouchard, D. C. (2002). Cosolvent effects on sorption isotherm linearity. J. Contam. Hydrol. 56(3 1), 159-174. 

It is possible that these results could be generalized to natural geological formations. Rather than describing a formation as a mixture of specific minerals, it might be possible to describe the formation as a mixture of types of adsorbents. These adsorbents could be characterized by experiments at low pH where oxide groups have little influence on sorption behavior and experiments at higher pH where the pH has a significant effect on sorption. 

Larsen T., Christensen T. H., Pfeifer F. M., and Enheld C. G. (1992) Landhll leachate effects on sorption of organic micropollutants onto aquifer materials. J. Contamin. Hydrol. 9, 307-324. 

The pH effects on sorption of ions have been interpreted in terms of ... 

In this present case, we will neglect any effects on sorption due to gross changes in structural/morphologlcal aspects of the polymer. The occurrence of such changes due to photodegradation would be expected to seriously affect other polymer properties of consequence for the application such as adhesion and Impact strength. This, of itself, would suffice to eliminate the material from consideration for the application. 

The effect on sorption of progressive changes in chemical group composition can be expressed quite simply by a weighted solubility coefficient ... 

Wood AL, Bouchard DC, Brusseau ML, Rao PSC (1990). Cosolvent effects on sorption and mobility of organic contaminants in soils. Chemosphere 21(4-5) 575-587. 

G. K. Fleming, W. J. Koros, Carbon dioxide conditioning effects on sorption and volume dilation behaviour for bisphenol A-polycarbonate, Macromolecules, 23, 1353 (1990). 

Most of the results reported herein on the sorption of polycations by natural keratins have been obtained on simplified model systems. The rationale behind such an approach was to seek to determine the fate of sorbing polymer under well-defined conditions and so to obtain mechanistic insight. The results have clearly indicated that both adsorption and absorption processes can occur. They have also shown that the nature, extent, and consequences of polycation sorption can all be influenced by the presence of surfactant. In general, nonionic surfactants have a small effect on sorption, because of low interaction while cationic surfactants can have a very large effect because of competition for the sorption sites. Because of interaction and complex formation with cationic polyelectrolytes anionic surfactants can exercise an intermediate, but potentially very important, influence. 

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