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R. L. Wershaw

Two examples of the interaction of pesticides with natural organic materials have been investigated. Sodium humate solubilizes DDT in water and humic acid strongly sorbs 2,4,5-T. These two types of interactions are indicative of the types that one would expect when any organic pesticide is applied to a natural soil-water system.
The chemical relationships among particulate and colloidal organic material and dissolved fulvic acid were examined in an alpine and subalpine lake and two streams in Loch Vale Watershed, Rocky Mountain National Park. The alpine lake, Sky Pond, had the lowest dissolved organic carbon (DOC) (0.37 mgC/L), the highest particulate carbon (POC) (0.13 mgC/L), and high algal biomass. The watershed of Sky Pond is primarily talus slope, and DOC and POC may be autochthonous. Both Andrews Creek and Icy Brook gain DOC as they flow through wet sedge meadows. The subalpine lake, The Loch, receives additional organic material from the surrounding forest and had a higher DOC (0.66 mgC/L). Elemental analysis, stable carbon isotopic...
Categories: Publication; Types: Citation; Tags: Biogeochemistry
An investigation of the aqueous chlorination (NaOCl) of resorcinol is reported. The following intermediates were detected in moderate to high yield at different pH values and varying percentages of chlorination: 2-chloro-, 4-chloro-, 2,4-dichloro-, 4,6-dichloro- and 2,4,6-trichlororesorcinol. Only trace amounts of the intermediates were detected when the chlorination was conducted in the presence of phosphate buffer. This result has significant implications since resorcinol in phosphate buffer has been used as a model compound in several recent studies on the formation of chlorinated hydrocarbons during chlorination of drinking water. Relative rates of chlorination were determined for resorcinol and several of the...
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Categories: Publication; Types: Citation; Tags: Analytical Chemistry
Aquatic humic substances, which account for 30 to 50% of the organic carbon in water, are a principal component of aquatic organic matter. The molecular size of aquatic humic substances, determined by small-angle X-ray scattering, varies from 4.7 to 33 A?? in their radius of gyration, corresponding to a molecular weight range of 500 to greater than 10,000. The aquatic fulvic acid fraction contains substances with molecular weights ranging from 500 to 2000 and is monodisperse, whereas the aquatic humic acid fraction contains substances with molecular weights ranging from 1000 to greater than 10,000 and is generally polydisperse. ?? 1982.
Categories: Publication; Types: Citation; Tags: Organic Geochemistry
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