Hydrolysis environmental fate

Wolfe NL. 1980. Organophosphate and organophosphorothionate esters Application of linear free energy relationships to estimate hydrolysis rate constants for use in environmental fate assessment. Chemosphere 9 571-579. 

Harvey J, JJ Dulka, JJ Anderson (1985) Properties of sulfometuroin methyl affecting its environmental fate aqueous hydrolysis and photolysis, mobility and adsorption on soils, and bioaccumulation potential. J Agric Food Chem 33 590-596. 

P.M. Jeffers and N.L. Wolfe, Hydrolysis of methyl bromide, ethyl bromide, chloropicrin, 1,4-dichloro-2-butene, and other halogenated hydrocarbons, in Fumigants Environmental Fate, Exposure, and Analysis, ed. J.N. Seiber, J.A. Knuteson, J.E. Woodrow, N.L. Wolfe, M.V. Yates, and S.R. Yates, ACS Symposium Series No. 652, American Chemical Society, Washington, DC, pp. 32-41 (1997). 

The environmental fate of a chemical is usually a function of many physical and chemical processes which the chemical may encounter from the time it is applied until it dissipates. Such processes include Photolysis on surfaces, in solution or in air, hydrolysis, biolysis, oxidation, transport by drift, erosion (runoff) and other means of transport and dissipation. Historically, most risk assessments have emphasized the toxicity of a chemical separately without adequate consideration of the amount of exposure to a chemical which an organism might... 

Environmental Fate. The fate of bromomethane in the environment is dominated by rapid evaporation into air, where it is quite stable (EPA 1986b). The rates of volatilization from soil and water have been studied and are known with reasonable precision (although such rates are typically site-specific) (Jury et al. 1984 Lyman et al. 1982). The rates of breakdown by hydrolysis, reaction with hydroxyl radical, and direct photolysis in the stratosphere have also been estimated (Castro and Belser 1981 Davis et al. 1976 Robbins 1976). Further studies to improve the accuracy of available rate constants for these processes would be helpful, but do not appear to be essential in understanding the basic behavior of bromomethane in the environment. 

Environmental fate Chemicals released in the environment are suscephble to several degradahon pathways, including chemical (i.e., hydrolysis, oxidation, reduction, dealkylahon, dealkoxylation, decarboxylahon, methylation, isomerization, and conjugation), photolysis or photooxidahon and biodegradation. Compounds transformed by one or more of these processes may result in the formation of more toxic or less toxic substances. In addihon, the transformed product(s) will behave differently from the parent compound due to changes in their physicochemical properties. Many researchers focus their attention on transformahon rates rather than the transformahon products. Consequently, only limited data exist on the transitional and resultant end products. Where available, compounds that are transformed into identified products as weh as environmental fate rate constants and/or half-lives are listed. 

A ranking of these pesticides with respect to ease of detoxification by hydrolysis can thus be used as a basis for determining treatment of drinking water, and can also be used to predict the relative environmental fate parameters. Assuming similar dependence of kgijg on 0H concentration for environmental pH values, the rankings obtained In this study can be applied to environmental conditions and can be useful for pesticide application decisions. ... 

No data were located regarding the hydrolysis of 1,3-DNB and 1,3,5-TNB. Flowever, neither compound is expected to undergo hydrolysis since aromatic nitro compounds are generally resistant to chemical hydrolysis under environmental conditions (Lyman et al. 1982). The transformation of 1,3-DNB in water due to reactions with oxidants present in natural bodies of water is not expected to be important in environmental fate processes (ERA 1991b). 

Environmental Fate. Extensive information is available on the general reactions of isocyanates that may pertain to the environmental fate of HDI (Chadwiek and Cleveland 1981 Kennedy and Brown 1992). However, investigations of the environmental fate of isocyanates have focused primarily on TDI and MDI (Duff 1983, 1985 Gilbert 1988 Holdren et al. 1984). Only one laboratory study was located in the available literature specifically on the ehemieal reaetions of HDI (i.e., bicarbonate buffer-catalyzed hydrolysis) that may be relevant to the environmental fate of HDI in water (Berode et al. 1991). HDI is expected to react relatively rapidly with hydroxyl radieals in the atmosphere and to be rapidly hydrolyzed in water and moist soils and sediment. The signifieanee of atmospheric hydrolysis has not been evaluated. Additional field and laboratoiy studies are needed to adequately eharacterize the environmental fate of HDI in air, water, soil, and sediment. 

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