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Environmental Chemistry Commons

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2007

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Articles 1 - 20 of 20

Full-Text Articles in Environmental Chemistry

Nirt: Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Phytoplankton In Marine Systems, Mark L. Wells, Karen Orcutt, D. Whitney King, Carl Tripp Dec 2007

Nirt: Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Phytoplankton In Marine Systems, Mark L. Wells, Karen Orcutt, D. Whitney King, Carl Tripp

University of Maine Office of Research Administration: Grant Reports

There is increasing evidence that Fe has a singularly unique role in marine ecosystems, both regulating total phytoplankton production in high nitrate, low chlorophyll regions of the world, and influencing the predominant composition of the phytoplankton assemblages found in others. It is remarkable then that there is no agreement about how to define biologically available Fe, in contrast to the macronutrients nitrogen, phosphorous or silicon. Current attempts to attain predictive insights to how ocean ecosystems will influence the magnitude of climate change are blocked in large part by this question, along with an extreme shortage of data on Fe distributions …


Evidence Of Recycling Of Lead Battery Waste Into Highly Leaded Jewelry, Jeffrey D. Weidenhamer, Micheal L. Clement Nov 2007

Evidence Of Recycling Of Lead Battery Waste Into Highly Leaded Jewelry, Jeffrey D. Weidenhamer, Micheal L. Clement

Jeffrey D. Weidenhamer

Inexpensive highly leaded jewelry, much of it imported from China, remains widely available in the United States. The source materials for these items are unknown. Due to the low cost of much of this trinket jewelry, it seems likely that scrap materials may be used in their manufacture. Thirty-nine jewelry items previously determined to contain 90% or more lead by weight were analyzed for antimony content. The average antimony content of these thirty-nine items was 3.0%. The range of antimony content in the samples was from 0.3% to 6.2% antimony by weight, with twenty-seven of the samples in the range …


Leaded Electronic Waste Is A Possible Material For Lead-Contaminated Jewelry, Jeffrey D. Weidenhamer, Michael L. Clement Oct 2007

Leaded Electronic Waste Is A Possible Material For Lead-Contaminated Jewelry, Jeffrey D. Weidenhamer, Michael L. Clement

Jeffrey D. Weidenhamer

Highly leaded jewelry, often imported from China, remains widely available in the United States. Leaded electronic waste is exported from the United States to several Asian countries where solder is recovered and circuit boards are stripped of parts in small workshops. To assess whether electronic waste is being recycled into the jewelry, lead, tin and copper content of highly leaded jewelry samples were determined by atomic absorption spectrometry. Sixteen jewelry items previously determined to contain 20–80% lead by weight were analyzed. Samples were digested in nitric acid for analysis of lead and copper, and in aqua regia for analysis of …


Organic Geochemical Investigation Of A Highly Contaminated Urban Waterway: The Gowanus Canal, Brooklyn, New York, Usa, Michael A. Kruge, Kevin K. Olsen, Eric A. Stern Sep 2007

Organic Geochemical Investigation Of A Highly Contaminated Urban Waterway: The Gowanus Canal, Brooklyn, New York, Usa, Michael A. Kruge, Kevin K. Olsen, Eric A. Stern

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Gowanus Canal is an industrial waterway constructed in the mid-19th century by widening and deepening a natural tidal channel. It is ca. 3 km in length and empties into Gowanus Bay, an arm of New York Harbor. Its banks, reinforced by bulkheads and piers, became the site of intensive industrial activity, including oil refining, coal gasification, soap making and tanning. Even though much of the industrial activity along the canal has ceased, its sediments remain highly enriched in organic and inorganic contaminants, with combined sewer outfalls continuing to transport pollutants into the canal. The canal area remains densely …


Sorption-Enhanced Steam Reforming Of Hydrocarbons With Autothermal Sorbent Regeneration In A Moving Heat Wave Of Catalytic Combustion Reaction, Andrey N. Zagoruiko, Alexey G. Okunev Jul 2007

Sorption-Enhanced Steam Reforming Of Hydrocarbons With Autothermal Sorbent Regeneration In A Moving Heat Wave Of Catalytic Combustion Reaction, Andrey N. Zagoruiko, Alexey G. Okunev

Andrey N Zagoruiko

Novel technological concept of sorption-enhanced hydrocarbon steam reforming with autothermal regeneration of the carbon dioxide scavenger in the moving super-adiabatic heat wave of the exothermic catalytic combustion reaction performed directly inside the adsorption-catalytic bed is presented. Process modelling results, confirming the capability and high efficiency of the proposed technological approach, are discussed. It is shown that proposed approach opens the way for creation of cheap, reliable and energy-saving adiabatic packed bed methane processors of unlimited processing capacity.


Groundwater Characterization At Yucca Mountain Task 2: Surface Complexation And Solid Phase Sorption, Kenneth Czerwinski, Anthony Hechanova, Amy J. Smiecinski May 2007

Groundwater Characterization At Yucca Mountain Task 2: Surface Complexation And Solid Phase Sorption, Kenneth Czerwinski, Anthony Hechanova, Amy J. Smiecinski

Publications (YM)

The purpose and scope of this report is to present an overview of the experiments, methods, results, and conclusions from research performed for the project “Groundwater Characterization at Yucca Mountain Task 2: Surface Complexation and Solid Phase Dissolution”. The impact of surface complexation, alteration phase formation, and solution competition with metal ions on the solubility and speciation of actinide elements (U, Pu, Np) will be examined. In particular the role of iron (as Fe2+ and Fe3+) and silicate (as SO3 2-) concentrations on speciation, solubility, sorption, and secondary phase formation of actinides will be investigated. While a large body of …


Basic Research Needs For Geosciences: Facilitating 21st Century Energy Systems, U.S. Department Of Energy, Office Of Basic Energy Sciences, Donald J. Depaolo, Franklin M. Orr Jr. Feb 2007

Basic Research Needs For Geosciences: Facilitating 21st Century Energy Systems, U.S. Department Of Energy, Office Of Basic Energy Sciences, Donald J. Depaolo, Franklin M. Orr Jr.

Publications (YM)

Executive Summary

Serious challenges must be faced in this century as the world seeks to meet global energy needs and at the same time reduce emissions of greenhouse gases to the atmosphere. Even with a growing energy supply from alternative sources, fossil carbon resources will remain in heavy use and will generate large volumes of carbon dioxide (CO2). To reduce the atmospheric impact of this fossil energy use, it is necessary to capture and sequester a substantial fraction of the produced CO2. Subsurface geologic formations offer a potential location for long-term storage of the requisite large …


Chemistry For A Sustainable Future, Julian Tyson Jan 2007

Chemistry For A Sustainable Future, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Investigating The Spring Bloom In San Francisco Bay: Links Between Water Chemistry, Metal Cycling, Mercury Speciation, And Phytoplankton Community Composition, Allison C. Luengen Jan 2007

Investigating The Spring Bloom In San Francisco Bay: Links Between Water Chemistry, Metal Cycling, Mercury Speciation, And Phytoplankton Community Composition, Allison C. Luengen

Environmental Science

Investigating the spring bloom in San Francisco Bay: Links between water chemistry, metal cycling, mercury speciation, and phytoplankton community composition This dissertation addresses the relationship between two problems facing estuaries nationwide: nutrient enrichment and metal contamination. The focus is on the southern reach of San Francisco Bay, where high nutrient concentrations can control the magnitude of the predictably occurring spring phytoplankton bloom. The bloom in this study, in spring 2003, was one of the largest blooms on record, exceeding 150 μg L -1 of chlorophyll α. As the bloom grew, diatoms (e.g. Thalassiosira punctigera ) depleted dissolved nutrients from the …


Chemical Analyses In Support Of Yucca Mountain Studies, Harry Reid Center For Environmental Studies, University Of Nevada, Las Vegas Jan 2007

Chemical Analyses In Support Of Yucca Mountain Studies, Harry Reid Center For Environmental Studies, University Of Nevada, Las Vegas

Publications (YM)

Research Objectives:

Provide preparation of injectates, sorption studies and analyses for tracer tests

Provide REE, trace metals, majors and field measurement data from wells of the Nye County Early Warning Drilling Program (NCEWDP)and Inyo County

Other laboratory needs as they arise


On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 7, September 2006, Gary A. Bishop, Ryan Stadtmuller, Donald H. Stedman Jan 2007

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 7, September 2006, Gary A. Bishop, Ryan Stadtmuller, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 6, November 2006, Gary A. Bishop, Ryan Stadtmuller, Donald H. Stedman Jan 2007

On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 6, November 2006, Gary A. Bishop, Ryan Stadtmuller, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Eddy Correlation Measurements Of The Air/Sea Flux Of Dimethylsulfide Over The North Pacific Ocean, Christa A. Marandino, Warren J. De Bruyn, Scott D. Miller, Eric S. Saltzman Jan 2007

Eddy Correlation Measurements Of The Air/Sea Flux Of Dimethylsulfide Over The North Pacific Ocean, Christa A. Marandino, Warren J. De Bruyn, Scott D. Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Shipboard measurements of air/sea fluxes and sea surface concentrations of dimethylsulfide (DMS) were made over the tropical and midlatitude North Pacific Ocean. Atmospheric pressure chemical ionization mass spectrometry was used to measure DMS levels in ambient air and in air equilibrated with surface seawater drawn from a depth of 5 m. Air/sea fluxes were obtained using eddy covariance. Corrections and uncertainties involved in the calculation of fluxes from shipboard data are discussed. The surface ocean DMS concentrations measured during this study ranged from 1 to 10 nM, and atmospheric mixing ratios ranged from 20 to 1000 ppt. Air/sea fluxes ranged …


On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Year 6, January 2007, Gary A. Bishop, Donald H. Stedman Jan 2007

On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Year 6, January 2007, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Fleet Vehicle Smoke Emissions As Measured By On-Road Remote Sensing Using Infrared Scattering: Years 1998 Through 2007, Jeffrey A. Caulfield, Gary A. Bishop, Donald H. Stedman Jan 2007

Fleet Vehicle Smoke Emissions As Measured By On-Road Remote Sensing Using Infrared Scattering: Years 1998 Through 2007, Jeffrey A. Caulfield, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Portable Emission Measurements Of Snowcoaches And Snowmobiles In Yellowstone National Park, Gary A. Bishop, Ryan Stadtmuller, Donald H. Stedman Jan 2007

Portable Emission Measurements Of Snowcoaches And Snowmobiles In Yellowstone National Park, Gary A. Bishop, Ryan Stadtmuller, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


A Novel Tio2 / Pvc Layer For Use In A Photoelectrochemical Cell, Faiza Touati, John Cassidy, Kevin Mcguigan Jan 2007

A Novel Tio2 / Pvc Layer For Use In A Photoelectrochemical Cell, Faiza Touati, John Cassidy, Kevin Mcguigan

Articles

A novel method of coating titanium dioxide on a glassy carbon electrode as a polyvinylchloride composite , is described. On illumination , there is an enhanced voltammetric current at this TiO2/PVC composite in aqueous formic acid solution. This electrode is used as the basis of a formic acid fuel cell where oxygen is reduced at a platinum cathode. The system yields 100 cm-2 for 0.01 mol dm-3 HCOOH in 0.1 mol dm-3 NaOH under illumination from a 150 W xenon lamp. The current without illumination is 0.5 cm-2.


An Experiment Using A Simple Photoassisted Fuel Cell Designed To Remediate Simulated Wastewater, John Cassidy, Faisa Touati, Kevin Mcguigan Jan 2007

An Experiment Using A Simple Photoassisted Fuel Cell Designed To Remediate Simulated Wastewater, John Cassidy, Faisa Touati, Kevin Mcguigan

Articles

Work in photochemistry work peaked in the 1980’s where there was the prospect of using sunlight shining on suspensions of titanium dioxide in order to catalytically cleave water into hydrogen and oxygen [1-5]. In this way a clean and efficient method of producing hydrogen as a fuel was envisaged. However, there was a requirement to use a rather high energy light to achieve the splitting and it was not as efficient with visible light[5]. Doped TiO2 layers have been used in a three electrode system for formic acid degradation[6]. In this work, the system uses an electrode coated with TiO2 …


Improved Nitrate Sensing Using Ion Selective Electrodes Based On Urea–Calixarene Ionophores, Benjamin Schazmann, Dermot Diamond Jan 2007

Improved Nitrate Sensing Using Ion Selective Electrodes Based On Urea–Calixarene Ionophores, Benjamin Schazmann, Dermot Diamond

Articles

Urea–calix[4]arenes 1 and 2 were synthesised and incorporated into ISE membranes for assessment as sensors for inorganic anions in water. 1 revealed a strong response to all anions following the Hofmeister selectivity order. For ISEs of 2, the response to a portion of the anion series was suppressed, increasing the margin of selectivity of nitrate over chloride, a common interferant of nitrate in fresh and marine water samples. The performance of ISEs containing 2 was compared to commercially available alkylammonium nitrate ion-exchange salts used for nitrate sensing. Our ISEs performed favourably in terms of sensitivity, linear range and LOD performing …


Determination Of Labetalol Hydrochloride In Drug Formulations By Spectrophotometry, Habibur Rahman Dr. Dec 2006

Determination Of Labetalol Hydrochloride In Drug Formulations By Spectrophotometry, Habibur Rahman Dr.

Habibur Rahman

No abstract provided.