TCE Removal Utilizing Coupled Zeolite Sorption and Advanced Oxidation

Trichloroethylene (TCE) is one of the most common groundwater pollutants in the United States. The EPA estimated that between 9% and 34% of the drinking water sources in the United States may contain TCE. The United States Environmental Protection Agency set a maximum contaminant level at 5 µg/L of trichloroethylene for drinking water. This study investigated the feasibility of removing TCE from water by sorption to ZSM-5 and advanced oxidation to destroy the TCE on the zeolite. Aqueous oxidation of TCE with Fenton’s reagent was shown to be efficient for the destruction of TCE. The quantified by-products were cis-DCE and trans-DCE. ZSM-5 rapidly removed TCE from water. A Freundlich isotherm was created for the uptake of TCE by ZSM-5. Once TCE was sorbed to ZSM-5, preliminary experiments showed that the oxidation was able to destroy the TCE while producing the same by-products

Polar organic compounds in fine particulate matter in the NJ-NY-CT transportation corridor

Fine particulate matter has been associated with adverse health effects, reduced visibility, haze and global climate change. Controlling sources of fine particles in urban and rural airsheds requires detailed knowledge of emission sources, including temporal and spatial distributions. Currently, about 20% of the organic mixtures associated with fine particles can be determined quantitatively as individual chemical species. Some compounds can be related to the emission source based on the chemical profile of that source, and are designated as molecular markers. Nonpolar and moderately polar molecular markers are used to apportion airborne fine particles to sources. Polar organic compounds are not well characterized in airsheds due to a wide range of chemical properties that introduce analytical complexity and difficulty. Consequently, emission sources that introduce polar carbonaceous matter into the atmosphere are not well understood and not effectively controlled. High performance liquid chromatography and gas chromatography-mass spectrometry were evaluated to determine the optimal method for characterizing polar organic compounds in fine particulate matter samples. Gas chromatography-mass spectrometry was chosen due to its capability to analyze a large range of chemical properties in one analysis. Samples were studied from metropolitan New York City area from six receptor locations, including upwind and downwind sites in NY, NJ and CT from May 2002 to February 2007. The results indicated spatial and seasonal trends for the molecular markers. Statistical analysis demonstrated seasonal variations of wood smoke at two sites (Westport, CT and Bronx, NY), meat charbroiling at only one site (Bronx, NY), and levulinic acid at three sites (Westport, CT, Bronx, NY and Pinnacle State Park, NY). When the samples were grouped as urban and rural areas the statistical analysis showed there was no spatial or seasonal trend in levoglucosan, total n-alkanols or levulinic acid. Wood smoke was higher for the NYC metropolitan and suburban sites than for the rural sites and found year-round. The levoglucosan, total n-alkanols, cholesterol, cis-pinonic acid and levulinic acid normalized to elemental carbon did show statistical differences between urban and rural sites, indicating the sites were influenced by local emission sources and meteorological conditions.Ph.D.Includes bibliographical references (p. 226-235)

Sequential Derivatization of Polar Organic Compounds in Cloud Water Using O-(2,3,4,5,6-Pentafluorobenzyl)hydroxylamine Hydrochloride, N, O-Bis(trimethylsilyl)trifluoroacetamide, and Gas-Chromatography/Mass Spectrometry Analysis

Cloud water samples from Whiteface Mountain, NY were used to develop a combined sampling and gas chromatography-mass spectrometric (GCMS) protocol for evaluating the complex mixture of highly polar organic compounds (HPOC) present in this atmospheric medium. Specific HPOC of interest were mono- and di keto-acids which are thought to originate from photochemical reactions of volatile unsaturated hydrocarbons from biogenic and manmade emissions and be a major fraction of atmospheric carbon. To measure HPOC mixtures and the individual keto-acids in cloud water, samples first must be derivatized for clean elution and measurement, and second, have low overall background of the target species as validated by GCMS analysis of field and laboratory blanks. Here, we discuss a dual derivatization method with PFBHA and BSTFA which targets only organic compounds that contain functional groups reacting with both reagents. The method also reduced potential contamination by minimizing the amount of sample processing from the field through the GCMS analysis steps. Once derivatized only gas chromatographic separation and selected ion monitoring (SIM) are needed to identify and quantify the polar organic compounds of interest. Concentrations of the detected total keto-acids in individual cloud water samples ranged from 27.8 to 329.3 ng mL-1 (ppb). Method detection limits for the individual HPOC ranged from 0.17 to 4.99 ng mL-1 and the quantification limits for the compounds ranged from 0.57 to 16.64 ng mL-1. The keto-acids were compared to the total organic carbon (TOC) results for the cloud water samples with concentrations of 0.607 to 3.350 mg L-1 (ppm). GCMS analysis of all samples and blanks indicated good control of the entire collection and analysis steps. Selected ion monitoring by GCMS of target keto-acids was essential for screening the complex organic carbon mixtures present at low ppb levels in cloud water. It was critical for ensuring high levels of quality assurance and quality control and for the correct identification and quantification of key marker compounds.Corrected proof of accepted manuscrip