Environmental chemodynamics

Thibodeaux, L. J. (1979). Chemodynamics, Environmental Movement of Chemicals in Air, Water, and Soil. New York Wiley. 

L. T. Thibodeaux, Environmental Chemodynamics Movement of Chemicals in Air, Water and Soil, 2nd edn, Wiley, New York, 1996. 

Gillett JW Cornell University, Ithaca, NY Biological responses associated with exposure, biodegradation and chemodynamics of lead National Institute of Environmental Health Sciences... 

Thibodeaux, L. J. (1996), Environmental Chemodynamics, John Wiley Sons, New York, p.593. 

The power of analytical instrumentation currently available makes it possible to detect organic pollutants at extremely low concentrations in various environmental samples [64, 362-365]. Such low detection limits are essential if pollutants are to be measured with the accuracy and precision required for modeling their chemodynamic behavior. Most of the work on organic analysis and characterization has resulted from the use of GC and GC-MS. 

Organic pollutants present in aqueous-solid phase environments and discussed in the present chapter include petroleum hydrocarbons, pesticides, phthalates, phenols, PCBs, chlorocarbons, organotin compounds, and surfactants. In order to study the chemodynamic behavior of these pollutants, it is important that (1) suitable pre-extraction and preservation treatments are implemented for the environmental samples, and (2) specific extraction and/or cleanup techniques for each organic pollutant are carried out prior to the identification and characterization steps. 

There are many areas into which environmental organic chemistry and environmental engineering can advance as a result of developments in various analytical techniques. All of this information will provide a much clearer picture on the chemodynamics of organic compounds, their biodegradation residues, and transformation products. Information such as this is important for modeling the fate and transport of organic compounds in the environment. 

Aboul-Kassim [1] studied the characterization, chemodynamics, and environmental impact assessment of organic leachates from complex mixtures. He reported that an important factor in controlling the rate of solid phase adsorption reactions is the type and quantity of solid phase components as well as the time period (i. e., short vs long) over which the organic contaminant has been in contact with the solid phase. 

On the other hand, Aboul-Kassim [1] assessed the environmental impact of hazardous waste materials in landfills by (1) characterizing the different organic compound fractions present in such wastes and their leachates, (2) determining the toxic effect of each fraction and individual organic compounds, and (3) studying the chemodynamics (i.e., fate and transport) of such leachates by using a battery of laboratory experiments (such as sorption/desorption, photolysis, volatilization, biodegradation). 

Recently, extensive research on partition coefficients has been developed in the field of medicinal chemistry because it has been observed that the action of drugs may be correlated with their partition coefficients. This parameter is an important component of structure-activity relationships (Sect. 2.2) for different series of biologically active compounds as well as for predicting environmental behavior and chemodynamics of complex mixtures [21, 62, 80-85, 88 - 90]. The octanol/water (K0Vf) system is used almost exclusively in such comparisons. 

Using predictive models for measuring environmental chemodynamics of organic pollutants in complex mixtures requires literature data on partition coefficient values. In some cases the values cited are not strictly experimental, being derived from linear free energy relations, while in others wide variations are reported in experimental values. The main problem is how one should evaluate which values are correct. Thus, Table 2 provides some basis to discriminate between reported values of partition coefficients, as well as predictive equations for partition coefficient calculations [21,62,65-85]. 

Whether a toxic pollutant in a COM or a solid waste material (SWM) leachate carries a charge or exists as a neutral species will have a dramatic effect on its environmental chemodynamics. This is a possibility with weak organic acids and bases, and is a function of the pK of the particular organic compound and pH of the surrounding environment. For instance, the dissociation of any weak organic acid (proton donor) may be represented as... 

Equation (25) can be used to calculate the composition of buffer solutions where pH is the dependent variable and [A ] and [HA] are variables which can be controlled experimentally. In environmental chemodynamics studies of complex organic mixtures, a relation expressing [A ] and [HA] as a function of pH and pK is needed. Providing the total concentration of the A containing species is Cx ... 

Freed, V.H., Chiou, C.T., andHaque, R. Chemodynamics transport and behavior of chemicals in the environment-A problem in environmental health. Environ. Health Perspect., 20 55-70,1977. 

Relate chemodynamics to both ecotoxicology and environmental chemistry. 

Freed, V.H., Kaufman, D.D., Metcalf, R.L., Farmer, W.J., Crosby, D.G., Spencer, W. (1976) Chemodynamics Transport and Behavior of Chemicals in the Environment - A Problem in Environmental Health. George Washington University Medical Center,... 

A Case Study in the Application of Environmental Chemodynamic Principles for the Selection of a Remediation Scheme at a Louisiana Superfund Site... 

A Case Study in the Application of Environmental Chemodynamic Principles... 

This chapter details the findings of the sorption/desorption hysteresis and desorption kinetic studies and how the results of these environmental chemodynamic studies impacted remediation of the PPI sites. The literature on the topic is presented below.. In the next section, we present some of the results of our research on sorption/desorption hysteresis and desorption kinetics for freshly contaminated soils as well as aged soils. The experimental protocols are published elsewhere [6-10]. 

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