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2007-4-18 EST最新文章和摘要
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Effects of Ethanol (E85) versus Gasoline Vehicles on Cancer and Mortality in the United States Mark Z. Jacobson* Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020 Received for review August 31, 2006 Revised manuscript received February 19, 2007 Accepted March 14, 2007 Abstract: Ethanol use in vehicle fuel is increasing worldwide, but the potential cancer risk and ozone-related health consequences of a large-scale conversion from gasoline to ethanol have not been examined. Here, a nested global-through-urban air pollution/weather forecast model is combined with high-resolution future emission inventories, population data, and health effects data to examine the effect of converting from gasoline to E85 on cancer, mortality, and hospitalization in the United States as a whole and Los Angeles in particular. Under the base-case emission scenario derived, which accounted for projected improvements in gasoline and E85 vehicle emission controls, it was found that E85 (85% ethanol fuel, 15% gasoline) may increase ozone-related mortality, hospitalization, and asthma by about 9% in Los Angeles and 4% in the United States as a whole relative to 100% gasoline. Ozone increases in Los Angeles and the northeast were partially offset by decreases in the southeast. E85 also increased peroxyacetyl nitrate (PAN) in the U.S. but was estimated to cause little change in cancer risk. Due to its ozone effects, future E85 may be a greater overall public health risk than gasoline. However, because of the uncertainty in future emission regulations, it can be concluded with confidence only that E85 is unlikely to improve air quality over future gasoline vehicles. Unburned ethanol emissions from E85 may result in a global-scale source of acetaldehyde larger than that of direct emissions. -------------------------------------------------------------------------------- Anaerobic Degradation of Linear Alkylbenzene Sulfonates in Coastal Marine Sediments Pablo A. Lara-Martín, Abelardo Gómez-Parra, Thorsten Köchling, José Luis Sanz, Ricardo Amils, and Eduardo Gonzlez-Mazo* Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cdiz, Campus Río San Pedro s/n, 11510 Puerto Real, Cdiz, Spain, and Unidad de Microbiología Aplicada, Centro de Biología Molecular, Universidad Autónoma de Madrid, Crta. de Colmenar km 15, 28049 Madrid, Spain Received for review October 4, 2006 Revised manuscript received January 22, 2007 Accepted March 9, 2007 Abstract: This research shows for the first time the degradation of linear alkylbenzene sulfonates (LAS) under anaerobic conditions, together with the presence of metabolites and the identification of microorganisms involved in this process. This compound is the most widely used surfactant and its main environmental concern is related to its persistence in the absence of oxygen as LAS accumulates in anaerobic sediments and sewage sludges. Laboratory experiments performed with anoxic marine sediments spiked with 10-50 ppm of LAS demonstrated, however, that its degradation reached 79% in 165 days via the generation of sulfophenyl carboxylic acids (SPCs). Almost all of the added LAS (>99%) was found to be attached to the sediment while the less hydrophobic SPCs were predominant in solution, as their concentration increased progressively up to 3 ppm during the full course of the experiment. Average half-life for LAS has been estimated to be 90 days, although higher values should be expected when the LAS concentration exceeds 20 ppm, due to inhibition of the microbial community. Sulfate-reducing and methanogenic activities proved to be intense during the experiment. Several sulfate-reducing bacteria and firmicutes/clostridia have been identified as possible candidates for effecting this degradation. Our results imply that the persistence of LAS in anoxic compartments, such as marine sediments, should be reconsidered when evaluating its environmental risk. -------------------------------------------------------------------------------- Quantum Chemical Modeling of Humic Acid/Air Equilibrium Partitioning of Organic Vapors Christian Niederer* and Kai-Uwe Goss* Institute of Biogeochemistry and Pollutant Dynamics, ETH-Zurich, Universitätsstrasse 16, CH-8092 Zurich, Switzerland Received for review October 18, 2006 Revised manuscript received March 5, 2007 Accepted March 6, 2007 Abstract: Classical approaches for predicting soil organic matter partition coefficients of organic compounds require a calibration with experimental partition data and, for good accuracy, experimental compound descriptors. In this study we evaluate the quantum chemical model COSMO-RS in its COSMOtherm implementation for the prediction of about 200 experimental Leonardite humic acid/air partition coefficients without calibration or experimental compound descriptors, but simply based on molecular structures. For this purpose a Leonardite Humic Acid model monomer limited to 31 carbon atoms was derived from 13C NMR analysis, elemental analysis, and acidic function analysis provided in the literature. Altogether the COSMOtherm calculations showed a good performance and we conclude that it may become a very promising tool for the prediction of sorption in soil organic matter for compounds for which the molecular structure is the only reliable information available. COSMOtherm can be expected to be very robust with respect to new and complex compound structures because its calculations are based on a fundamental assessment of the underlying intermolecular forces. In contrast, other empirical models that are also based on the molecular structure of the sorbate have an application domain that is limited by their calibration data set that is often unknown to the user. -------------------------------------------------------------------------------- Monitoring the Primary Biodegradation of Linear Alkylbenzene Sulfonates and Their Coproducts in Anoxic Sediments Using Liquid Chromatography-Mass Spectrometry Pablo A. Lara-Martín, Abelardo Gómez-Parra, Thorsten Köchling, José Luis Sanz, and Eduardo Gonzlez-Mazo* Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cdiz, Campus Río San Pedro s/n, 11510 Puerto Real, Cdiz, Spain, and Unidad de Microbiología Aplicada, Centro de Biología Molecular, Universidad Autónoma de Madrid, Crta. de Colmenar km 15, 28049 Madrid, Spain Received for review October 4, 2006 Revised manuscript received January 22, 2007 Accepted March 9, 2007 Abstract: An accompanying article has demonstrated the anaerobic degradation of the surfactant linear alkylbenzene sulfonate (LAS) in microcosms filled with marine sediments through the generation of sulfophenylcarboxylic acids (SPCs). A detailed study shows that this process was uniform in the blanks (non-spiked natural sediments) for every LAS homologue during the complete course of the experiment. However, when sediments were spiked with commercial LAS and, therefore, enriched with short-chain homologues, degradation was enhanced for these homologues until their percentages were close to those for non-spiked sediments. The reason is that short-chain homologues are more bioavailable due to their higher solubility and lower sorption capacity. Thus, sorption on sediments was found to be increased with the length of the alkyl chain for LAS homologues, following a linear Freundlich isotherm, whereas the metabolites generated were predominant in solution due to their much higher polarity. Intermediate-chain SPC homologues (C7-C9 SPCs) were the most abundant during the experiment, but a significant increase in the concentration of shorter-chain SPC homologues (C4-C6 SPCs) was detected toward the end. In the case of isomers, the steric effect of the aromatic group implies that LAS primary degradation took place preferentially over external isomers. Therefore, the generation of external isomers of SPCs was predominant during the complete experiment although internal isomers of SPCs became more evident when the degradation process had advanced and external isomers of LAS became scarce. The identity of both types of SPC isomer was confirmed by tandem mass spectrometry. With respect to LAS coproducts, the relative percentage of iso-LAS increased during the complete experiment and removal percentages for dialkyl tetralinsulfonates (<30%) were typically lower that those for LAS (66-79%), although a similar behavior was observed for their homologues in both cases. -------------------------------------------------------------------------------- |
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Perfluoroalkyl Contaminants in the Canadian Arctic: Evidence of Atmospheric Transport and Local Contamination Naomi L. Stock, Vasile I. Furdui, Derek C. G. Muir, and Scott A. Mabury* Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada, and Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Drive, Burlington, Ontario L7R 4A6, Canada Received for review November 13, 2006 Revised manuscript received February 22, 2007 Accepted March 4, 2007 Abstract: Perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) have been hypothesized to reach remote locations such as the Canadian Arctic either indirectly as volatile precursor chemicals that undergo atmospheric transport and subsequent degradation, or directly via oceanic and atmospheric transport of the PFSAs and PFCAs themselves. Water, sediment, and air samples were collected from three Arctic lakes (Amituk, Char, and Resolute) on Cornwallis Island, Nunavut, Canada. Samples were analyzed for PFSAs and PFCAs, precursor chemicals including the fluorotelomer alcohols (FTOHs) and polyfluorinated sulfonamides (FSAs), and precursor degradation products such as the fluorotelomer unsaturated carboxylates (FTUCAs). PFSAs and PFCAs were detected in water and sediment of all three Arctic lakes (concentrations ranged from nondetect to 69 ng/L and nondetect to 85 ng/g dry weight, respectively). FTOHs and FSAs were observed in air samples (mean concentrations ranged from 2.8 to 29 pg/m3), and confirm that volatile precursors are reaching Arctic latitudes. The observation of degradation products, including FTUCAs observed in sediment and atmospheric particles, and N-ethyl perfluorooctanesulfonamide (NEtFOSA) and perfluorooctanesulfonamide (PFOSA) in air samples, indicate that degradation of the FTOHs and FSAs is occurring in the Arctic environment. PFSAs and PFCAs were also observed on atmospheric particles (mean concentrations ranged from <0.1 to 5.9 pg/m3). In addition, results of this study also indicate that local perfluoroalkyl contamination of Resolute Lake, which is located downstream of an airport wastewater input, has occurred. -------------------------------------------------------------------------------- Hyperbranched Poly(-caprolactone) as a Nonmigrating Alternative Plasticizer for Phthalates in Flexible PVC Jeongsoo Choi and Seung-Yeop Kwak* Hyperstructured Organic Materials Research Center (HOMRC), and School of Materials Science and Engineering, Seoul National University, San 56-1, Shillim-dong, Gwanak-gu, Seoul 151-744, Korea Received for review November 13, 2006 Revised manuscript received February 22, 2007 Accepted March 19, 2007 Abstract: Hyperbranched (dendritic) poly(-caprolactone)s (HPCLs) were synthesized to have architectural variations, which are the different lengths of linear segments and different numbers of branches, and were used as plasticizers for flexible poly(vinyl chloride) (PVC). The plasticization efficiency estimated by the lowering of glass transition temperature and the enhancement in ultimate elongation indicated that the HPCLs with the shorter linear segments and the larger number of branches imparted as high flexibility as di(ethylhexyl) phthalate (DEHP) and much higher flexibility than their linear analogue, linear poly(-caprolactone), which is one of currently used polymer plasticizers. Volatility, extractability, and exudation tests for PVC/HPCL samples showed that there was no plasticizer migration even at very harsh condition, while ca. 7-78% of additives in PVC/DEHP was migrated out of samples, indicating that the HPCL can be used as an alternative plasticizer to remove the potential health risk from migrating phthalates during end use. -------------------------------------------------------------------------------- Synthetic Musk Fragrances in Human Milk from the United States Jessica L. Reiner, Chung M. Wong, Kathleen F. Arcaro, and Kurunthachalam Kannan* Wadsworth Center, New York State Department of Health and Department of Environmental Health Sciences, State University of New York at Albany, Empire State Plaza, PO Box 509, Albany, New York 12201-0509, and Department of Veterinary and Animal Sciences, University of Massachusetts-Amherst, Amherst, Massachusetts 01003 Received for review December 27, 2006 Revised manuscript received March 8, 2007 Accepted March 13, 2007 Abstract: Synthetic musk compounds are used as additives in many consumer products, including perfumes, deodorants, and detergents. Earlier studies have reported the occurrence of synthetic musks in environmental and wildlife samples collected in the United States. In this study, human breast milk samples collected from Massachusetts, were analyzed for the determination of concentrations of synthetic musks such as musk xylene (1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene), musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone), HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[]-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), and HHCB-lactone, the oxidation product of HHCB. In addition, we estimated the daily intake of synthetic musks by infants based on the ingestion rate of breast milk. Synthetic musks were found in most of the samples analyzed, and the concentrations ranged from <2 to 150 ng musk xylene/g, <2 to 238 ng musk ketone/g, <5 to 917 ng HHCB/g, <5 to 144 ng AHTN/g, and <10 to 88.0 ng HHCB-lactone/g, on a lipid weight basis. The concentrations of HHCB were higher than the concentrations of other synthetic musks in breast milk samples. The mean concentration of HHCB (220 ng/g, lipid weight) was 5 times greater than the concentrations reported 10 years ago for breast milk samples collected in Germany and Denmark. Maternal age was not correlated with the concentrations of musk xylene, musk ketone, HHCB, or AHTN. There was a trend of decreasing concentrations of musk xylene, musk ketone, HHCB, and AHTN, with the number of children previously breast-fed, although the correlation was not significant. Based on average daily ingestion rate of breast milk, an infant is estimated to ingest 297 ± 229 ng musk xylene, 780 ± 805 ng musk ketone, 1830 ± 1170 ng HHCB, 565 ± 614 ng AHTN, and 649 ± 598 ng HHCB-lactone per day. The ingestion rate of synthetic musks by infants in the United States is lower than that estimated for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs). Based on the residue patterns and accumulation features, it can be concluded that the exposure characteristics for synthetic musks are different from those of POPs, and that the major source of exposure to synthetic musks is probably via dermal absorption or inhalation. -------------------------------------------------------------------------------- Deposition of Glomalin-Related Soil Protein and Sequestered Toxic Metals into Watersheds Eunice C. Chern, Diana W. Tsai, and Oladele A. Ogunseitan* Department of Environmental Health, Science, and Policy and Public Health Program, College of Health Sciences, University of California at Irvine, Irvine, California 92697-7070 Received for review December 2, 2006 Revised manuscript received March 14, 2007 Accepted March 15, 2007 Abstract: We hypothesized that glomalin-related soil proteins (GRSP) are eroded in sufficient quantities to influence metal loading into watersheds. We tested correlations among GRSP, Glomeromycota fungi, and metals (cadmium, iron, lead, and manganese) in proteins extracted from embankment soils at seven locations along an urban/coastal watershed. Immunoreactive (IRSP) and easily extractable (EE-IRSP) glomalin ranged from 0.007 to 2.9 mg g-1 and from 0.006 to 0.63 mg g-1 of soils, respectively. Glomalin-bound metals (g mg-1 protein) were Cd = 0.00-0.338; Fe = 0.5-227.7; Pb = 0.11-188.95; Mn = 2.23-784.42). Glomeromycota fungi were detected in 24% of all samples tested with PCR targeting the 18S and 28S ribosomal DNA extracted from soils. Specific assay for G. intraradices showed 3.08 × 107 copies g-1 and 1.96 × 103 copies g-1 of soil at two sites. Estimated annual glomalin loading into the watershed ranged from 5.48 × 102 to 7.22 × 104 kg of IRSP and from 2.57 × 102 to 2.86 × 104 kg of EE-IRSP; including 2.7 kg (Cd), 6.3 × 103 kg (Fe), 5.06 × 102 kg (Pb), and 1.80 × 103 kg (Mn). These data provide insights into the sources and ecological fate of a ubiquitous soil protein and its metals content. -------------------------------------------------------------------------------- Prevalence of Long-Chained Perfluorinated Carboxylates in Seabirds from the Canadian Arctic between 1975 and 2004 Craig M. Butt, Scott A. Mabury, Derek C.G. Muir, and Birgit M. Braune* Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada, Water Science and Technology Branch, Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada, and National Wildlife Research Centre, Environment Canada, Carleton University, Raven Road, Ottawa, Ontario K1A 0H3, Canada Received for review November 13, 2006 Revised manuscript received February 26, 2007 Accepted March 4, 2007 Abstract: Temporal trends in perfluoroalkyl compounds (PFCs) were investigated in liver samples from two seabird species, thick-billed murres (Uria lomvia) and northern fulmars (Fulmaris glacialis), from Prince Leopold Island in the Canadian Arctic. Thick-billed murre samples were from 1975, 1993, and 2004, whereas northern fulmars were from 1975, 1987, 1993, and 2003. Between 8 and 10 individuals were analyzed per year. Analytes included C7-C15 perfluorinated carboxylates (PFCAs) and their suspected precursors, the 8:2 & 10:2 fluorotelomer saturated and unsaturated carboxylates (FTCAs, FTUCAs), C6, C8 (perfluorooctane sulfonate, PFOS), C10 sulfonates, and perfluorooctane sulfonamide (PFOSA). Liver samples were homogenized, liquid-liquid extracted with methyl tert-butyl ether, cleaned-up using hexafluoropropanol, and analyzed by LC-MS/MS. Overall, concentrations in seabirds were lower than those in other marine animals that occupy similar or higher trophic positions. In contrast to most other wildlife samples, PFC profiles were dominated by the PFCAs which comprised 81% and 93% of total PFC profiles in the 2004 thick-billed murre and 2003 northern fulmar samples, respectively. As well, the PFCA profiles were mainly comprised of the C11-C15 PFCAs, which appears to be unique among other wildlife species. PFC concentrations were found to increase significantly from 1975 to 2003/2004. Doubling times in thick-billed murres ranged from 2.3 yrs for perfluoropentadecanoate (PFPA) to 9.9 yrs for perfluorododecanoate (PFDoA), and from 2.5 yrs for PFPA to 11.7 yrs for perfluorodecanoate (PFDA) in northern fulmars. PFCA concentration increases in thick-billed murres were significant for both time periods (19751993, 19932004), but in northern fulmars appeared to remain steady after 1993. Differences in the temporal trends observed may be the result of differing migratory patterns of the seabirds. Finally, the detection of the 8:2 and 10:2 FTUCAs in seabirds is suggestive of fluorotelomer alcohols as a source of some PFCAs. -------------------------------------------------------------------------------- Relationship between The Adsorption Capacity of Pesticides by Wood Residues and The Properties of Woods and Pesticides Sonia Rodriguez-Cruz, Maria S. Andrades, Maria Sanchez-Camazano, and Maria J. Sanchez-Martin* Instituto de Recursos Naturales y Agrobiología, CSIC. Apdo, 257, 37071 Salamanca, Spain and Departamento Agricultura y Alimentación, Universidad de La Rioja, Madre de Dios, 51, 26006 Logroño, Spain Received for review October 31, 2006 Revised manuscript received January 25, 2007 Accepted February 16, 2007 Abstract: With the aim to explore the potential use of wood residues in technologies aimed at preventing the pollution of soil and water, we studied the adsorption of four non-ionic pesticides (linuron, alachlor, metalaxyl, and chlorpyrifos) and two ionic pesticides (dicamba and paraquat) with a Kow range of -4.5 to 4.7 by nine types of wood with lignin content in the 18.2-26.9% range. The Freundlich Kf values were considered as indicators of the adsorption capacity. A statistical study was carried out using simple and multiple correlations to establish the degree to which the different parameters of the woods and of the pesticides were involved in adsorption. In the case of the non-ionic pesticides, positive and negative significant correlations were observed between Kf and the lignin (r = 0.73-0.83, p < 0.05-0.01), and soluble C contents of the woods (r = 0.66-0.84), p < 0.1-0.01). For dicamba, a correlation between Kf and pH (r = -0.66, p < 0.1) of the woods was found, while for paraquat, this was seen between Kf and the cation exchange capacity (r = 0.71, p < 0.1) of the woods. No significant correlation was observed between Kf and the total C content of the woods. A highly significant correlation between Kf and Kow values (r 0.93, p < 0.01) was found in the adsorption of the pesticides by the woods (with the exception of paraquat) showing that this parameter is very important in this adsorption process. The determination coefficient of the multiple correlation between Kf and the parameters Kow, soluble C, and lignin contents accounts for nearly 100% of the variability in adsorption for non-ionic pesticides. Based on the results of our study and of those of the literature related to the adsorption of aromatic hydrocarbons, we used the Kow values to define a predictive model of adsorption of hydrophobic organic compounds in general by the woods. -------------------------------------------------------------------------------- |
2楼2007-04-18 23:23:04
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FeCl3/NaNO2: An Efficient Photocatalyst for the Degradation of Aquatic Steroid Estrogens under Natural Light Irradiation Lianzhi Wang, Feifang Zhang, Renhua Liu,* Tony Y. Zhang, Xingya Xue, Qing Xu, and Xinmiao Liang* Dalian Institute of Chemical Physics, the Chinese Academy of Sciences, Dalian 116023, P.R. China, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P.R. China, and Eli Lilly and Company, Indianapolis, Indiana 46285 Received for review October 27, 2006 Revised manuscript received March 12, 2007 Accepted March 16, 2007 Abstract: Assistance and acceleration of the environment's self-remediation of pollutants represent an important and long-standing goal for environmental chemistry communities. Here, a degradation route using a combination of a nitrite and a ferric salt as the photocatalyst is presented for catalytically removing 17-estradiol (E2), estriol (E3), and 17-ethynylestradiol (EE2) in water under mimicked natural environmental conditions, i.e., in the phytotron. After a 1 day reaction, 86.6% of the estrogen E2 was degraded. Extending the incubation time to 30 days, more than 99.9% E2 was removed and a very small quantity of malonic acid observed as the residual organic compound, and estrogenic activity was determined. The results showed that the estrogenic activities of the intermediate products are negligible and that there is no secondary risk associated with increased the estrogenic activity. The degradation system demonstrated that FeCl3/NaNO2 is an efficient photocatalyst which is active on natural light irradiation. This work highlights a promising development for in situ treatment of pollutants in natural-environment conditions. -------------------------------------------------------------------------------- |
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