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[资源] 2007-4-21 EST最新文章和摘要

Fingerprinting Localized Dioxin Contamination: Ichihara Anchorage Case

Minori Uchimiya,* Mari Arai, and Shigeki Masunaga

Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan

Received for review December 18, 2006

Revised manuscript received March 19, 2007

Accepted March 22, 2007

Abstract:

Although concentrations of polychlorinated dibenzo-p-dioxins and dibezofurans (PCDD/Fs; dioxins) in majority of Japanese river and ocean sediments decreased below the national environmental quality standard of 150 pg-TEQ·(g-dry sediment)-1 by 2004, localized contamination inasmuch as 100-fold excess of the environmental quality standard has been reported at various locations including Ichihara Anchorage in northeastern Tokyo Bay. In the present study, we analyzed all mono- to octachlorinated dioxins in 12 surface sediments from Ichihara Anchorage and applied positive matrix factorization (PMF) to quantitatively fingerprint the congener pattern and geographical distribution of a factor causing the localized contamination. A PMF-derived fingerprint attributable to dioxin impurities in pentachlorophenol (PCP) exerted more than 90% contribution to total dioxin concentrations in Ichihara Anchorage surface sediments. Although majority of Ichihara Anchorage-born dioxins were trapped at the origin, contribution of the PCP-derived dioxins in overall Tokyo Bay gradually increased toward Ichihara Anchorage, indicating the impact of localized dioxin contamination on a large proportion of Tokyo Bay. We suggest that, in addition to runoff from rice paddies (to which PCP had long been applied as herbicide) at the basin, Ichihara Anchorage serves as a significant source of PCP-derived dioxins especially in eastern Tokyo Bay.


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Fate of Endocrine Disrupting Compounds in Membrane Bioreactor Systems

J. Y. Hu,* X. Chen, G. Tao, and K. Kekred

Division of Environmental Science and Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, and Centre for Advanced Water Technology, Singapore Utilities International Pte Ltd., Blk 2, #241, Innovation Centre (NTU), 18 Nanyang Drive, Singapore 637723

Received for review November 11, 2006

Revised manuscript received March 13, 2007

Accepted March 19, 2007

Abstract:

Yeast estrogen screen (YES) bioassay and liquid chro matography-mass spectrum-mass spectrum (LC-MS-MS) analysis were performed to investigate the fate of active and potential endocrine disrupting compounds in 3 pilot-scale and 2 lab-scale membrane bioreactor (MBR) systems. Compared with the overall estrogenicities of sewage treatment plant (STP) effluents from references, the MBR systems studied have relatively good performance in the removal of estrogenicity. Estrone (E1) was removed with relatively high efficiency (80.2-91.4%), but 17-estradiol (E2) was removed with moderate efficiency (49.3-66.5%) by the MBRs. However, the experimental results indicated that after the treatment by MBR, substantial amounts of E1, estrone-3-sulfate (E1-3S), estrone-3-glucuronide (E1-3G), and 17-estradiol-glucuronides (E2-G) passed through treatment systems and entered into the aquatic environment. The reduction in the levels of overall equivalent E1 (68.4%) and that of overall equivalent E2 (80.8%) was demonstrated for the pilot-scale MBR-B. For alkylphenol compounds, bisphenol A (BPA) was removed well with a removal efficiency of 68.9 -90.1%, but 4-nonylphenol (4-NP) concentration was amplified (removal efficiency of -439.5 to -161.1%) after MBR treatment which could be caused by the transformation of its parent compounds, nonylphenol polyethoxylates (NPnEOs). The amounts of adsorbed estrogens per kg dry mass was relatively low, due to short hydraulic retention time and high mixed liquor suspended solids in MBRs, compared to that in STPs.


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