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Occurrence and exposure to polycyclic aromatic hydrocarbons and their derivatives in a rural Chinese home through biomass fuelled cooking Полный текст
2012
Ding, Junnan | Zhong, Junjun | Yang, Yifeng | Li, Bengang | Shen, Guofeng | Su, Yuhong | Wang, Chen | Li, Wei | Shen, Huizhong | Wang, Bin | Wang, Rong | Huang, Ye | Zhang, Yanyan | Cao, Hongying | Zhu, Ying | Simonich, Staci L.M. | Tao, Shu
The concentration and composition of PAHs emitted from biomass cooking fuel were characterized in a rural non-smoking household in northern China. Twenty-two parent PAHs (pPAHs), 12 nitro-PAHs (nPAHs), and 4 oxy-PAHs (oPAHs) were measured in the kitchen, bedroom, and outdoors during both summer and winter. The most severe contamination occurred in the kitchen in the winter, where the daily mean concentrations of pPAHs, nPAHs, and oPAHs were 7500 ± 4100, 38 ± 29, and 8400 ± 9200 ng/m³, respectively. Our results suggest that the nPAHs were largely from secondary formation in ambient air while oPAHs were either from primary emission of biomass burning or secondary formation from pPAHs in the kitchen. The daily mean benzo(a)pyrene equivalent exposure concentration was as high as 200 ± 160 ng/m³ in the winter for the housewife who did the cooking compared to 59 ± 37 ng/m³ for the control group that did not cook.
Показать больше [+] Меньше [-]Polycyclic aromatic hydrocarbons on indoor/outdoor glass window surfaces in Guangzhou and Hong Kong, south China Полный текст
2012
Pan, Su-Hong | Li, Jun | Lin, Tian | Zhang, Gan | Li, Xiang-Dong | Yin, Hua
Organic films were collected from indoor and outdoor window surfaces in two large cities in southern China, Guangzhou and Hong Kong, and analyzed to quantify the polycyclic aromatic hydrocarbons (PAHs). In the glass films, the highest concentration of total PAHs, predominantly phenanthrene, fluorene, fluoranthene, and pyrene, was found to be l400 ng/m². The concentrations of PAHs in Guangzhou were usually higher than those in Hong Kong. In general, higher concentrations of PAHs on exterior window films in comparison with interior window films in both cities indicated that the outdoor air acted as a major source of pollution to the indoor environment. However, indoor air was a major source of some light-weight PAHs. Measurements made over time indicated that the growth rates of light-weight PAHs on window surfaces were fast at the beginning and then gradually reached a consistent level, whereas heavy-weight PAHs exhibited near-linear accumulation during the 40 days sampling period.
Показать больше [+] Меньше [-]Atmospheric fate of poly- and perfluorinated alkyl substances (PFASs): I. Day–night patterns of air concentrations in summer in Zurich, Switzerland Полный текст
2012
Müller, Claudia E. | Gerecke, Andreas C. | Bogdal, Christian | Wang, Zhanyun | Scheringer, Martin | Hungerbühler, Konrad
Poly- and perfluorinated alkyl substances (PFASs) are anthropogenic pollutants ubiquitously found in the environment. Volatile PFASs are likely transported atmospherically over long ranges, but identification and quantification of emission sources is a challenging task. In this work, special meteorological conditions were utilized to quantify atmospheric emissions of Zurich City, Switzerland with a dual approach of modeling and field measurements. During high pressure systems in summer, a stable nocturnal boundary layer is formed in which pollutants are enriched. For volatile PFASs, a diel pattern of high concentrations in the night and low concentrations during the day was observed in Zurich, which is likely due to the atmospheric boundary layer dynamics. These results enable to model the emission source strength of Zurich City with a multimedia mass balance model in an accompanying paper. Cluster analyses suggested that perfluorocarboxylates (PFCAs) are a result of degradation of volatile precursors and direct emissions.
Показать больше [+] Меньше [-]Regional variation and possible sources of brominated contaminants in breast milk from Japan Полный текст
2012
Fujii, Yukiko | Ito, Yoshiko | Harada, Kouji H. | Hitomi, Toshiaki | Koizumi, Akio | Haraguchi, Koichi
This study focuses on the regional trends and possible sources of brominated organic contaminants accumulated in breast milk from mothers in southeastern (Okinawa) and northwestern (Hokkaido) areas of Japan. For persistent brominated flame retardants, polybrominated diphenyl ethers (PBDEs; major components, BDE-47 and BDE-153) were distributed at higher levels in mothers from Okinawa (mean, 2.1 ng/g lipid), while hexabromobenzene (HeBB) and its metabolite 1,2,4,5-tetrabromobenzene were more abundantly detected in mothers from Hokkaido (0.86 and 2.6 ng/g lipid), suggesting that there are regional differences in their exposure in Japan. We also detected naturally produced brominated compounds, one of which was identified as 2′-methoxy-2,3′,4,5′-tetrabromodiphenyl ether (2′-MeO-BDE68) at higher levels in mothers from Okinawa (0.39 ng/g lipid), while the other was identified as 3,3′,4,4′-tetrabromo-5,5′-dichloro-2,2′-dimethyl-1,1′-bipyrrole in mothers from Hokkaido (0.45 ng/g lipid). The regional variation may be caused by source differences, i.e. southern seafood for MeO-PBDEs and northern biota for halogenated bipyrroles in the Japanese coastal water.
Показать больше [+] Меньше [-]Remediation of copper in vineyards – A mini review Полный текст
2012
Mackie, K.A. | Müller, T. | Kandeler, E.
Viticulturists use copper fungicide to combat Downy Mildew. Copper, a non-degradable heavy metal, can accumulate in soil or leach into water sources. Its accumulation in topsoil has impacted micro and macro organisms, spurring scientists to research in situ copper removal methods. Recent publications suggest that microorganism assisted phytoextraction, using plants and bacteria to actively extract copper, is most promising. As vineyards represent moderately polluted sites this technique has great potential. Active plant extraction and chelate assisted remediation extract too little copper or risk leaching, respectively. However, despite interesting pot experiment results using microorganism assisted phytoextraction, it remains a challenge to find plants that primarily accumulate copper in their shoots, a necessity in vineyards where whole plant removal would be time consuming and financially cumbersome. Vineyard remediation requires a holistic approach including sustainable soil management, proper plant selection, increasing biodiversity and microorganisms.
Показать больше [+] Меньше [-]Behaviour of metalloids and metals from highly polluted soil samples when mobilized by water – Evaluation of static versus dynamic leaching Полный текст
2012
Wennrich, Rainer | Daus, Birgit | Müller, Karsten | Stärk, Hans-Joachim | Brüggemann, Lutz | Morgenstern, Peter
The mobilization behaviour of metalloids and metals when leached by water from highly polluted soil/sediment samples was studied using static and dynamic approaches employing batch methodology and rotating coiled columns (RCC), respectively. Increasing the solution-to-solid ratios during batch leaching resulted in different enhanced mobilization rates, which are element-specific and matrix-specific. When dynamic leaching is employed with continuous replacement of the eluent, a higher portion is mobilized than when using batch elution with an identical solid-to-water ratio. Using RCC the time-resolved leaching of the elements was monitored to demonstrate the leaching patterns. For the majority of elements a significant decrease could be shown in the mobilized portion of the elements with ongoing leaching process. The data were discussed targeted at solid liquid partitioning coefficients of the metal(loid)s. The capabilities in application of Kd values was demonstrated for dynamic leaching which is relevant for environmental processes.
Показать больше [+] Меньше [-]A GIS technology based potential eco-risk assessment of metals in urban soils in Beijing, China Полный текст
2012
Wang, Meie | Bai, Yanying | Chen, Weiping | Markert, Bernd | Peng, Chi | Ouyang, Z. (Zhiyun)
Ecological risks of heavy metals in urban soils were evaluated using Beijing, China as an example. Cadmium, Cu, Zn, Pb, Cr and Ni contents of 233 surface soils sampled by 1 min latitude × 1 min longitude grid were used to identify their spatial distribution patterns and potential emission sources. Throughout the city, longer the duration of urbanization greater was the accumulations of heavy metals especially, Cd, Cu, Pb, and Zn. The soil Zn mainly came from the wears of vehicular tires. Point source emissions of heavy metals were few and far in the downwind south–east quadrant of Beijing. The calculated risk indices showed potential median eco-risks in the ancient central city. No potential high eco-risk due to soil-borne heavy metals was found. The potential medium eco-risk areas in Beijing would expand from the initial 24 to 110 km² if soil pH were to reduce by 0.5 units in anticipation.
Показать больше [+] Меньше [-]Polycyclic aromatic hydrocarbons in upstream riverine runoff of the Pearl River Delta, China: An assessment of regional input sources Полный текст
2012
Zhang, Kai | Liang, Bo | Wang, Ji-Zhong | Guan, Yu-Feng | Zeng, E. Y. (Eddy Y.)
Water samples collected from upstream tributaries of the Pearl River Delta (PRD) and from locations within the PRD (South China) were analyzed for 27 polycyclic aromatic hydrocarbons (PAHs). Average concentrations (aqueous plus particulate) of total 27 PAHs (Σ₂₇PAH), 16 priority PAHs designated by the United States Environmental Protection Agency (USEPA) except naphthalene (Σ₁₅PAH), and the seven carcinogenic PAHs (Σ₇PAH) classified by the USEPA were 260 ± 410, 130 ± 310, and 15 ± 12 ng/L, respectively. Riverine PAHs were predominantly generated from coal and vegetation combustion, coke production, vehicle exhausts, and petroleum residues, accounting for 28%, 25%, 22% and 21%, respectively, on average. Upstream riverine fluxes of Σ₂₇PAH and Σ₁₅PAH amounted to 38.9 and 12.9 tons/year, respectively. The net contributions of Σ₂₇PAH and Σ₁₅PAH from sources within the PRD were estimated at 21.4 and 21.0 tons/year, respectively.
Показать больше [+] Меньше [-]Remediation of cadmium-contaminated soil by extraction with para-sulphonato-thiacalix[4]arene, a novel supramolecular receptor Полный текст
2012
Li, Yushuang | Hu, Xiaojun | Song, Xueying | Sun, Tieheng
Batch extractions were conducted to evaluate the performance of para-sulphonato-thiacalix[4]arene (STC[4]A), a novel supramolecular receptor, for removing cadmium (Cd) from soil. The extraction mechanism was investigated by determination of the conditional stability constants (log K) of the STC[4]A-Cd complex. The influences of various variables were examined, including pH, contact time, and extractant concentration. The Cd extraction efficiency increased with increasing pH, reaching the maximum at pH 11 and then declining at higher pH values. This pH dependence was explained by the variation in the log K value of the STC[4]A-Cd complex along with pH change. When the STC[4]A dose was increased to an STC[4]A:Cd molar ratio of 2.5:1, Cd was exhaustively removed (up to 96.8%). The comparison experiment revealed that the Cd extraction performance of STC[4]A was almost equivalent to that of EDTA and significantly better than that of natural organic acids. STC[4]A extraction could efficiently prevent co-dissolution of soil minerals.
Показать больше [+] Меньше [-]Impacts of oil sands process water on fen plants: Implications for plant selection in required reclamation projects Полный текст
2012
Pouliot, Rémy | Rochefort, Line | Graf, Martha D.
Fen plant growth in peat contaminated with groundwater discharges of oil sands process water (OSPW) was assessed in a greenhouse over two growing seasons. Three treatments (non-diluted OSPW, diluted OSPW and rainwater) were tested on five vascular plants and four mosses. All vascular plants tested can grow in salinity and naphthenic acids levels currently produced by oil sands activity in northwestern Canada. No stress sign was observed after both seasons. Because of plant characteristics, Carex species (C. atherodes and C. utriculata) and Triglochin maritima would be more useful for rapidly restoring vegetation and creating a new peat-accumulating system. Groundwater discharge of OSPW proved detrimental to mosses under dry conditions and ensuring adequate water levels would be crucial in fen creation following oil sands exploitation. Campylium stellatum would be the best choice to grow in contaminated areas and Bryum pseudotriquetrum might be interesting as it has spontaneously regenerated in all treatments.
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