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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Distribution and Flux of the Polycyclic Aromatic Hydrocarbons of Kao-ping Estuary System

Wu, Sih-pei 06 February 2006 (has links)
Water, suspended particle and sediment samples from Kao-ping estuary were collected and measured for concentrations of polycyclic aromatic hydrocarbons (PAHs) during March 2004 and April 2005. In addition, sediments from neighboring coastal area were also analyzed to estimate distribution, transportation and possible sources of PAHs. Total PAH concentrations varied from 33.0 to 910 ng/g dry weight (dw) in coastal sediments, and diagnostic ratios reflect a mixed sources of petrogenic and pyrolytic inputs. Due to the contribution of Kao-ping River, spatial distribution of PAH concentrations at coastal sediments near river mouth varied dramatically. Results of hierachical cluster analysis showed that PAH concentration distribution was influenced by Kao-ping canyon, and biogenic source might be the major PAH source for offshore sediments. Total PAH concentrations in river sediment varied from 63.0 to 720 ng/g dw. Higher concentration was measured between the Water Main pipe and Shuang-yuan Bridge, and possible sources were from both petrogenic and pyrolytic sources. Sediment of Dung-gang harbour had highest concentration, 28,000ng/g dw, in this study, which was contributed from petrogenic sources due to its intensive boating activities. Except fluorene and phenanthrene in harbour sediments, individual PAH concentrations of other sediments are lower or near the Effect Range Low value, concentrations might lead to possible adverse effects upon organism. Total PAH concentrations varied from 5.0 to 82.0 ng/L in suspended particulate phase and from 5.5ng/L to 46.0ng/L in dissolved phase, respectively. Most of high molecular weight PAH concentrations (>5-ring PAHs) in dissolved phase were below method detection limits. The partition coefficients¡]Koc¡^values of PAHs were 1 to 2 orders higher than predicted values. It might be attributed to soot particles which have extremely high sorption capacities. Correlation coefficients between total PAH concentrations in sediments versus total organic carbon¡]TOC¡^ and fine particle content¡]<63£gm%¡^were significant ¡]R=0.575, 0.800, 0.851 and 0.657, P<0.01¡^. In addition, PAHs in suspended particulate phase and dissolved phase were also significantly correlated to particulate organic carbon¡]POC¡^ and dissolved organic carbon¡]DOC¡^, respectively. The distribution of calculated PAH concentrations from organic carbon was higher in surface water than bottom water. Unlike salinity, there was no decreasing or increasing trend of these concentrations among river samples. It is possible that contamination was not come from upstream, but from estuary area where plume was lifted and diffused upstream by neat seawater. The flux in Wan-da Bridge was higher than downstream estuary area that might be due to PAH concentrations reduction by sedimentation or degradation.
2

Distribution and characteristics of black carbon in sediments of Kao-ping Coastal Areas

Wu, Wen-Jing 28 August 2006 (has links)
The objective of this study was to investigate the spatial and temporal distribution of black carbon (BC) and possible sources by analyzing BC contents in core and sediment trap samples collected from Kao-ping submarine Canyon and surficial sediments collected from Love River, Chianjen River, Kaohsiung Harbor, Kao-ping River and adjacent coastal area. In addition, sediment core and trap samples of Kao-ping submarine Canyon, and suspended solids of Kao-ping estuary were analyzed to estimate the BC loading from Kao-ping River and the flux in Kao-ping submarine Canyon. The concentrations of BC ranged from 0.38 to 3.29 mg g-1 in this study. The results we found in coastal sediments were comparable to those in Asia, but lower than those in America and Europe. Black carbon found in surficial sediments of D2, L1 and of stations from Love River, Chianjen River and Kaohsiung Harbor were contributed from vehicle emission or coal combustion. Correlation coefficients of BC versus total polycyclic aromatic hydrocarbon (PAH) concentrations, combustion PAHs, total organic carbon (TOC) and grain size were significant in the sediments of Kao-ping River adjacent coast. Regrading to the temporal distribution of BC in Kao-ping submarine Canyon, BC and PAHs increased in the deposited sediment after 1970, that was probably related to prosperous industrial activities for last decades in Taiwan. Surficial sediments could be grouped into three clusters by hierarchical cluster analysis (HCA). Results of principal component analysis (PCA) showed principal component 1 (PC 1) could explain 35 % of total variances. Significant PC 1 compound loadings were found mostly from high molecular weight PAHs which derived mainly from combustion processes. This result was supported by the significant correlation (p<0.05) of PC 1 scores versus BC concentrations which were also mainly derived from combustion. BC fluxes for sediment cores, S1 and S37, and sediment trap of Kao-ping submarine Canyon, 0.59 g m-2 yr-1, 2.03 g m-2 yr-1 and 23 g m-2 yr-1, respectively, were comparable to those reported for surficial sediments in literature. However, BC fluxes in this study were lower than those in the sediments from Mouth of Providence River, Palos Verdes Shelf and New England Harbors, but higher than those in pelagic sediments of the Pacific Ocean. In addition, we also measured BC concentrations in suspended solid samples to estimate loadings of Kao-ping estuary which ranged from 33 to 1765 kg day-1 with an average of 602 kg day-1. Annual BC loading of Kao-ping River was roughly estimated as 29.55¡Ñ104 tons which was lower than that of the Mississippi River.

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