Wan Ying Shiu

A critical review of Henry’s law constants for chemicals of environmental interest

The Henry’s law constants (air‐water partition coefficients) of hydrophobic organic compounds of environmental concern are reviewed. An outline of the thermodynamic principles which govern the relationships between vapor pressure, solubility and Henry’s law constant for solid and liquid compounds is presented and experimental techniques for obtaining these quantities with the required accuracy are discussed. Vapor pressure, solubility, and Henry’s law constant data are tabulated and reviewed for a total of 150 compounds in 12 tables consisting of gaseous, liquid and solid alkanes, cycloalkanes, alkenes, alkynes, monoaromatics, polynuclear aromatics, halogenated alkanes, alkenes and aromatics, and selected pesticides.

Relationships between octanol-water partition coefficient and aqueous solubility

The thermodynamic relationship between octanol-water partition coefficient and aqueous solubility is discussed in the light of recently measured data for highly hydrophobic chemicals. Experimental data indicate that the presence of dissolved octanol in water has little effect on the solubility of chemicals in water and that the presence of dissolved water in octanol has little effect on the solubility of chemicals in octanol. The activity coefficients of hydrophobic chemicals in aqueous solution and in octanol solution both increase with increased chemical molar volume. An approximately linear relationship between log activity coefficient and molar volume is suggested in both phases, a consequence of which is that a plot of log octanol-water partition coefficient vs. log liquid or subcooled liquid solubility has a slope of approximately -0.8. A molecular thermodynamic interpretation of the data is presented, and some environmental implications are discussed.

Handbook of Physical-Chemical Properties and Environmental Fate for Organic Chemicals

VOLUME I Introduction The Incentive Physical-Chemical Properties Experimental Methods Quantitative Structure-Property Relationships (QSPRs) Mass Balance Models of Chemical Fate Data Sources and Presentation Illustrative QSPR Plots and Fate Calculations References Aliphatic and Cyclic Hydrocarbons Lists of Chemicals and Data Compilations Summary Tables and QSPR plots References Mononuclear Aromatic Hydrocarbons Lists of Chemicals and Data Compilations Summary Tables and QSPR plots References Polynuclear Aromatic Hydrocarbons (PAHs) and Related Aromatic Hydrocarbons Lists of Chemicals and Data Compilations Summary Tables and QSPR plots References VOLUME II * Halogenated Aliphatic Hydrocarbons Chlorobenzenes and Other Halogenated Mononuclear Aromatics Polychlorinated Biphenyls (PCBs) Chlorinated Dibenzop-dioxins Chlorinated Dibenzofurans VOLUME III * Ethers Alcohols Aldehydes and Ketones Carboxylic Acids Phenolic Compounds Esters VOLUME IV Nitrogen and Sulfur Compounds Lists of Chemicals and Data Compilations Summary Tables References Herbicides Lists of Chemicals and Data Compilations Summary Tables References Insecticides Lists of Chemicals and Data Compilations Summary Tables References Fungicides Lists of Chemicals and Data Compilations Summary Tables References APPENDICES List of Symbols and Abbreviations Alphabetical Index CAS Registry Index Molecular Formula Index * Each chapter contains lists of chemicals and data compilations, summary tables, QSPR plots, and references

A Critical Review of Aqueous Solubilities, Vapor Pressures, Henry’s Law Constants, and Octanol–Water Partition Coefficients of the Polychlorinated Biphenyls

Relationships between the environmentally relevant physical chemical properties of the polychlorinated biphenyls, namely, aqueous solubility, vapor pressure, Henry’s law constant, and octanol–water partition coefficient are discussed. Reported experimental data are tabulated and critically reviewed. Recommended values are given for 42 of the 209 congeners; however, procedures are suggested for estimating the properties of the other congeners. Properties of mixtures are not treated.

A review of the nature and properties of chemicals present in pulp mill effluents

A compilation is presented of some 250 chemicals identified in the effluents from pulp mills. The chemicals are categorized and available data on their environmentally relevant properties tabulated, including water solubility, vapour pressure, dissociation constant, and octanol-water partition coefficient. Data are also presented on the amounts produced, bioconcentration potential, and toxicity. It is concluded that available data on individual compound properties is not adequate to permit accurate assessments of environmental fate or effects. The number of chemicals is so large that there is a need to develop comprehensive quantitative structure-property-activity relationships to enable properties to be predicted rather than measured. Further, novel methods are needed to enable the cumulative effects of these many chemicals to be assessed, rather than treating chemicals on an individual basis.

A review of the effect of salts on the solubility of organic compounds in seawater

Abstract The presence of electrolytes (salts) in aqueous solution modifies the solubility and related properties of organic compounds in water. Reported data for salting-out constants (Setschenow constants) which relate solubility to the salt concentration of aromatic and alkane hydrocarbons, and their chlorinated derivatives, and some organic acids have been compiled for 25 aqueous salt solutions at 20–25 °C. The salting-out sequences for various electrolytes are discussed and it is shown that the salting-out effect is greater for organic solutes with large molar volumes. A compilation of salting-out constants for NaCl solutions and seawater (natural or synthetic) with a variety of solutes, shows that the Setschenow constants are similar for natural or artificial seawater (at salinity of 30–35%.) and NaCl solutions (at 3.0–3.5% or 0.5 M). A simple correlation is suggested for estimating the Setschenow constants for a variety of organic solutes in seawater which typically yields a reduction in solubility by a factor of 1.36. The hydrophobicity of organic solutes is therefore increased by this factor, as is the air-water partition coefficient, implying an increased partitioning from aqueous solution into air, organic carbon and lipid phases. The effect must be quantified when comparing the behavior of organic contaminants in freshwater and marine conditions.

Critical Review of Henry’s Law Constants for Pesticides

Pesticides play an important role in maintaining agricultural productivity, but they may also be causes of contamination of air, water, soil, and food, with possible adverse effects on human and animal health. The proper use of pesticide chemicals must be based on an understanding of the behavior of the chemicals as they interact with air, water, soil, and biota, react or degrade, and migrate. This behavior is strongly influenced by the chemicals’ physical-chemical properties of solubility in water, vapor pressure or volatility, and tendency to sorb to organic and mineral matter in the soil.

Relationships between aqueous solubility and octanol-water partition coefficients

Abstract The physical chemical equations relating solubility to octanol water partition coefficient are presented and used to develop a new correlation between these quantities which includes a melting point (fugacity ratio) correction. The correlation is satisfactory for 45 organic compounds but it is not applicable to organic acids. When applied to very high molecular weight (> 290) compounds the correlation is less satisfactory; either it is believed because the data are inaccurate or because the tendency for these compounds to partition into organic phases is less than expected. This may have profound environmental implications.

Uptake of organic chemicals by plants: a review of processes, correlations and models.

Abstract A review is presented of the mechanisms of uptake of organic chemical contaminants by plants from soil and the atmosphere. Correlations of uptake characteristics as a function of physical chemical properties are described and discussed, from which it is concluded that the key chemical parameters are likely to be octanol-water and octanol-air partition coefficients. Characteristics of available and emerging whole-plant models are discussed. A compilation of 150 references is provided documenting the fate of 70 chemicals in 88 species of plants and trees.

Generic models for evaluating the regional fate of chemicals

Abstract Level I, II, and III fugacity models are described in which the fate of a chemical is evaluated in a regional 100,000 km2 environment. Input data include the chemicals physical chemical properties and reaction half-lives. It is suggested that the Level III model which treats inter-media transport rates using a set of typical transport velocity parameters provides the most valuable insights into chemical fate, especially if discharges to the four primary media of air, water, soil and sediment are considered separately. The evaluation approach is illustrated for selected chlorobenzenes and p-cresol.