Physico-chemical Model of Toxic Substances in the Great Lakes

Physico-chemical Model of Toxic Substances in the Great Lakes PDF Author: Robert V. Thomann
Publisher:
ISBN:
Category : Water
Languages : en
Pages : 356

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Physico-chemical Model of Toxic Substances in the Great Lakes

Physico-chemical Model of Toxic Substances in the Great Lakes PDF Author: Robert V. Thomann
Publisher:
ISBN:
Category : Water
Languages : en
Pages : 356

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The Distribution and Behavior of Synthetic Musk Compounds in San Francisco Bay

The Distribution and Behavior of Synthetic Musk Compounds in San Francisco Bay PDF Author: Sarah Amy Rubinfeld
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 144

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Book Description
Synthetic musk fragrances are used in a wide variety of consumer products and can enter aquatic environments through wastewater effluent. Limited data are available on the distribution and behavior of these chemicals, especially in solid matrices and with respect to use patterns and distribution in the United States. Improving our understanding of the environmental fate of musk compounds has implications for risk assessment of both musks and other emerging contaminants. Although nitromusks are known to be hydrophobic, little attention has been paid to their behavior in sediments. A sediment extraction method using sonication was developed and used to analyze samples from San Francisco Bay. Two nitromusk compounds were measured at low levels, with the highest concentrations found in the southernmost region of the Bay. Samples were also analyzed from a nearby tidal channel fed by a wastewater treatment plant outfall, where nitromusks were found at slightly higher concentrations. A nitromusk metabolite was present at concentrations above its parent compound, suggesting that these metabolites may play an important role in the fate of nitromusk compounds. Concentrations of all three compounds were highest at the earliest of four sampling dates, and a geographic survey of sediments along the tidal channel showed that concentrations decreased rapidly with distance from the outfall and were close to background before the channel reached the Bay. To determine if the same pattern existed in other effluent-fed channels, a second study was performed adjacent to another local wastewater outfall. At this site both nitro and polycyclic musks were analyzed, and concentrations in water and suspended solids were measured in addition to sediment. Nitromusk concentrations were lower than at the first field site, and the distribution pattern was noticeably different. In the sediment, concentrations were lowest adjacent to the outfall and increased with distance both up and downstream. Polycyclic musks were present at much higher concentrations and showed a similar distribution pattern in sediment. Concentrations in suspended solids were highest near the outfall and decreased with distance. Aqueous concentrations generally decreased with distance from the source; however, the pattern was much more complex than the one seen at the first field site. A mass-balance computer model was developed to predict the environmental fate of hydrophobic chemicals in rivers and tidal channels. The model was applied to galaxolide at the second field site in hopes of explaining the chemical distribution pattern seen in the field measurements. The results captured the magnitude and some of the observed concentration patterns, but the model was less successful at matching the detailed distribution. An examination of the contaminant mass flows and dimensionless mass transfer parameters suggests that tidal dispersion, settling, and resuspension are the dominant mass transport mechanisms. An unsteady version of a tidal dispersion model was also developed and applied to a tracer in the same system. The results suggest that sampling at neap tide may be preferable to sampling at spring tide since there is less variation in concentration, and that channel branches play an important role and should be considered in future work. Using the model and dimensionless parameters to evaluate important mass transport mechanisms provides valuable information on which processes and parameters have the largest impact on contaminant fate. These insights can be used to adapt and improve the model and to suggest experimental designs to maximize the benefits of future sampling studies.

Selected Water Resources Abstracts

Selected Water Resources Abstracts PDF Author:
Publisher:
ISBN:
Category : Hydrology
Languages : en
Pages : 772

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ORD Publications Announcement

ORD Publications Announcement PDF Author: Center for Environmental Research Information (U.S.).
Publisher:
ISBN:
Category : Environmental engineering
Languages : en
Pages : 28

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Manmade Organic Compounds in the Surface Waters of the United States

Manmade Organic Compounds in the Surface Waters of the United States PDF Author: James Albert Smith
Publisher:
ISBN:
Category : Organic compounds
Languages : en
Pages : 104

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See journals under US Geological survey. Circular 1007.

Erosion and Sedimentation Manual

Erosion and Sedimentation Manual PDF Author:
Publisher: Government Printing Office
ISBN:
Category : Science
Languages : en
Pages : 626

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Book Description
NOTE: NO FURTHER DISCOUNT FOR THIS PRINT PRODUCT--OVERSTOCK SALE --Significantly reduced list price while supplies last The Erosion and Sedimentation Manual provides a comprehensive coverage of subjects in nine chapters (i.e., introduction, erosion and reservoir sedimentation, noncohesive sediment transport, cohesive sediment transport, sediment modeling for rivers and reservoirs, sustainable development and use of reservoirs, river process and restoration, dam decommissioning and sediment management, and reservoir surveys and data analysis). Each chapter is self-contained, with cross references of subjects that are discussed in different chapters of this manual. The manual also includes a list of commonly used notations used in the erosion and sedimentation literature, conversion factors between the Imperial and metric units, physical properties of water, and author and subject indexes for easy reference. Each chapter has a list of reference for readers who would like to seek out more detailed information on specific subjects. Audience The manual would be useful for researchers, university professors, graduate students, geologists, hydrographic survey analysts, municipal and state water research specialists, and engineers in solving erosion and sedimentation problems. Related products: Earth Science resources collection can be found here: https: //bookstore.gpo.gov/catalog/science-technology/earth-science

Monthly Catalogue, United States Public Documents

Monthly Catalogue, United States Public Documents PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1252

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Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 676

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Sediments and Water Interactions

Sediments and Water Interactions PDF Author: Peter G. Sly
Publisher: Springer Science & Business Media
ISBN: 1461249325
Category : Science
Languages : en
Pages : 514

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Book Description
The first symposium on sediment/freshwater interactions was held in Amsterdam, in 1976, and the second was held at Kingston, Ontario, Canada, in 1981. The third symposium was held at the University of Geneva, in 1984, and also included a num ber of contributions dealing with sediment/saltwater interactions. It is expected that future symposia of this series will retain this approach, and that the revised sympo sium title will remain the same for later proceedings of these meetings. Because of the large number of submissions in 1984, many were given as poster presentations. Extended abstracts of all contributions to the Geneva symposium appear in Interactions Between Sediments and Ubter (C. E. P. Consultants Ltd. , 26 Albany St. , Edinburgh, EHI 3QH, U. K. , 1984). Full-length papers appear only in the proceedings. The format of the third symposium was similar to its predecessors. The location provided a particularly good opportunity for attendance by European scientists, who represented about 81% of the participants. About 16% came from North America and 3% were from Southeast Asia and Australia. It is unfortunate that there were no contributors from either Africa or South America, or other parts of Asia. In all, 16 countries were represented at this symposium. In a continuing attempt to provide equal opportunities for attendance by scientists from other parts of the world, it is planned to hold the next symposium in Australia in 1987. Further information about the symposia series can be obtained from Dr. E. D.

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 1154

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