The distribution of mercury in the sediment of Keelung harbor

• Main Authors: Po-Min Hsu, 許博閔
• Other Authors: Tien-Hsi Fang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/62670124407860450452

碩士 === 國立臺灣海洋大學 === 海洋環境資訊學系 === 97 === The present study used the sequential extraction method to chemically separate the mercury in surface sediments from the Keelung Harbor into five species: water soluble; ‘human stomach acid’ soluble; organo-chelated; elemental Hg; and mercuric sulfide. In addition, the total concentrations of Hg in sediment samples were also analyzed. The concentrations of Hg in the extracted solutions were determined by the cold vapor atomic fluorescence spectrometry method. The total concentrations of mercury in surface sediments of the Keelung Harbor ranged within 106-1918 ng/g. The spatial distribution exhibited higher concentrations located in the river mouth within the harbor and the concentration decrease seaward along the channel. The total concentrations of mercury at the most studied stations exceeded the NOAA guideline value of incidence of adverse biological “effect range-low” (150 ng/g, Long et al., 1995). This result provides a warming signal that the Keelung Harbor has been contaminated by Hg. The percentage ranges of different species of Hg were as follows: water soluble, 0.06~6.17%; ‘human stomach acid’ soluble, <0.49%; organo-chelated, 9.56~51.85%; elemental Hg, 9.92~61.76% and mercuric sulfide, 7.05~64.28%. The fraction of mercuric sulfide dominated the Hg concentration in the Keelung Harbor, probably attributing to anaerobic environment within the harbor.