Polychlorinated biphenyl isomers: photolysis in aqueous systems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24520/1/0000799.pd

Influence of humic substances on photolysis of nitroaromatic compounds in aqueous systems

Results are reported for kinetic studies of the photolysis of 19 nitroaromatic compounds in water. The results indicate that dissolved humic substances in natural waters enhance the sunlight-induced photodegradation rates of nitrobenzenes, nitrotoluenes, and nitroxylenes compared to rates observed in distilled water. The largest enhancements, ranging from 2 to 26-fold, were observed for nitroaromatics that are methylated ortho to the nitro group. Similar enhancement effects were observed for humic substances obtained from a variety of terrigenous sources, including humus in natural waters and humus extracted from soils.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26131/1/0000207.pd

Distribution coefficients for chemical components of a coal-oil/water system

Distribution coefficients (KDS) were measured by equilibrating a coal oil comparative reference material (CRM-1) with water and then separating the oil and water phases. Aqueous phase concentrations were determined by direct analysis of this phase, while organic phase concentrations were determined from the original oil composition by difference. The log KD values obtained for acidic and basic components were generally KD and log Sw (water solubility), and between log KD and log KD and log Kow (octanol/water partition coefficient). Alkylated benzenes had significantly higher KDS than did unsubstituted aromatics of similar molecular weight. Examination of homologs revealed an increase of 0.307 log KD units per additional carbon atom for polynuclear aromatic hydrocarbons having from 10 to 16 carbons. Alkyl substituent effects determined for various sets of homologs ranged from 0.391 to 0.466 log Kd units per--CH2--group added.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27171/1/0000168.pd

Effects of chlorinated benzenes on diatom fatty acid composition and quantitative morphology. III. 1,2,3-Trichlorobenzene

Cells of the diatom Cyclotella meneghiniana were exposed in a closed system to 0.245 ppm 1,2,3-trichlorobenzene. Response of the diatom was measured by quantitative ultrastructure and fatty acid percent composition over a 5-day period. During that time, 35 significant morphological and 12 fatty acid percent composition changes occurred. The most pronounced morphological change that occurred was a significant increase in lipid volume. In addition, changes were observed in vacuolar relative volume, suggesting that the tonoplast became more permeable. Fewer significant changes were observed in fatty acid percent composition upon exposure to this isomer. However, there was a consistent increase in oleic acid (C18∶1). The observed changes in morphological and fatty acid percent composition were uniformly distributed with time after the first hour of exposure. Results support the hypothesis that increased lipid stores may alter the timing of response to lipophilic toxicants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48071/1/244_2005_Article_BF01225003.pd

Association studies of polybrominated biphenyls in aquatic systems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47983/1/128_2005_Article_BF01606089.pd

Effects of chlorinated organics from wastewater treatment on algal growth

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47982/1/128_2005_Article_BF01770039.pd

Hazardous Waste Measurements

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The production of bromophenols resulting from the chlorination of waters containing bromide ion and phenol

The formation of 2,4,6-tribromophenol is shown to result from the chlorination of water containing phenol and bromide ion at pH 7.4. Direct bromination with hypobromous acid is compared with bromination by hypochlorous acid and bromide ion. Under conditions where HOCl is not limiting, a higher yield of bromine substitution products can be expected from bromination by HOCl + Br- than by direct bromination by HOBr.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23398/1/0000343.pd

The effect of food consumption on the toxicokinetics of benzo(a)pyrene and 2,2',4,4',5,5'-hexachlorobiphenyl in

The relative importance of water and ingested food as possible avenues of contaminant accumulation was examined. was exposed to two representative non-polar contaminants: benzo(a)pyrene (BaP) and 2,2',4,4',5,5'-hexachlorobiphenyl (HCB). The accumulation was examined kinetically in the presence and absence of two food types, (water flea) and (a diatom). The availability of either food enhanced HCB accumulation and reduced BaP accumulation. Feeding did not affect HCB elimination but enhanced BaP elimination. The BaP was eliminated primarily as metabolites. Essentially all of the elimination occurred via the fecal route for both compounds. The fraction of the accumulation via ingestion of contaminated food was greater when mysids fed on than and was greater for HCB than BaP.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29930/1/0000287.pd