利用生物指標探討水庫過去環境型態

Biomarker molecule proxies of aliphatic hydrocarbons from a reservoir

王壬新(Wang, Rensin)

指導教授 ： 范誠偉

國立中正大學/理學院/地球與環境科學系應用地球物理與環境科學研究所/碩士(2012年)

摘要

本研究主要分析台灣翡翠水庫顆粒物質之脂肪族碳氫化合物 (aliphatic
hydrocarbons compositions, AHCs) C10 至C35 直鏈烷濃度及組成，藉由生物指標
(bio-marker)觀念以評估顆粒物質中有機物質來源及相對貢獻量。樣品包含沉積
物、20 及70 公尺深沉降顆粒、表水、20 及70 公尺深懸浮顆粒，其中沉積物2002
年採樣，沉降顆粒及懸浮顆粒為2004~2005 年採樣之樣品。分析前處理包括索氏
萃取，銅粒除硫及管柱淨化等，以氣相層析儀及火焰離子偵測器 (GC-FID) 進行
化學分析。沉積物總直鏈烷濃度平均為3.8±2.6 μg/g (n=12)，直鏈烷優勢種順序
為C31、C33、C29、C35、C27，佔總直鏈烷濃度約60%，CPI (Carbon preference index)
平均值為4.16±0.57 (n=12)，顯示中、長碳鏈奇數碳直鏈烷之生物來源訊號明顯；
TAR (Terrigenous to Aquatic Ratio) 平均值為15.3±22.74，整體以陸生貢獻長碳鏈
直鏈烷為主。70 公尺沉降顆粒總直鏈烷平均濃度為13.39±11.80 μg/g (n=9)，加權
平均濃度為8.23 μg/g，直鏈烷優勢種順序為C31、C20、C19、C29、C18，佔總直鏈
烷濃度約44%，顯示70 公尺沉降顆粒直鏈烷組成以長碳鏈之奇數碳C29、C31 及
短碳鏈C18、C19、C20 為主，CPI 平均值為4.07±1.52 (n=9)，加權平均為4.18，顯
示中、長碳鏈直鏈烷之生物來源訊號明顯，推測翡翠水庫沉積物之顆粒來源主要
為颱風事件70 公尺沉降顆粒所貢獻，並攜帶水庫周遭陸生微管束植物所貢獻長
碳鏈之奇數碳直鏈烷。懸浮顆粒總直鏈烷平均濃度253.01±159.34 μg/g (n=9)，直
鏈烷優勢種順序為C28、C29、C27、C26、C25，佔總直鏈烷濃度約54%；CPI 平均
值1.13±0.14 (n=9)，顯示懸浮顆粒直鏈烷組成以中、長碳鏈為主且無奇偶相對優
勢，並說明中、長碳鏈直鏈烷無明顯生物來源訊號，其中短碳鏈C17 為水中藻類
所貢獻。

關鍵字

脂肪族碳氫化合物

並列摘要

Aliphatic hydrocarbon compositions (AHCs, C10-C35 n-alkanes ) from a sediment core, suspended solids and settling particles of the Feitsui reservoir were Soxhlet extracted and GC-FID analyzed. The calculated biomarker molecule proxies were used to indicate the organic matter origins and their relative contributions. The total AHCs concentrations from sediments averaged 3.8±2.6μg/g(n=12), primarily dominating by the odd long-chain n-alkanes, such as C31、C33、C29、C35 and C27, approximately 60% of the total AHCs concentrations. The predominance of odd long-chain n-alkanes suggests the major contribution from terrestrial plants. The averaged CPI (Carbon preference index) value of 4.2±0.6 and the averaged TAR (Terrigenous to Aquatic Ratio) value of 15.3±22.74 also supported the obvious biogenetics features from terrestrial plants. The sampled settling particle represented 20% of annual settling fluxes and the total AHCs averaged 8.23μg/g weighted by particle settling fluxes. The averaged CPI value of 4.07±1.52 and the predominance of odd long-chain (C27、C29、C31 ) indicated biogenetics feature that AHCs in settling particles from terrestrial plants, corresponding to the main source of Feitsui Reservoir sediment is settling from those particles contributed by typhoon and carried terrestrial plants surrounding reservoir. The total AHCs concentrations of sampled suspended solid averaged 253.01±159.3 4μg/g (n=9) and the averaged CPI value of 1.13±0.14(n=9), indicated minor biogenetic feature in the suspended solid. However, the detected odd-short-chain n-alkane of C17 suggested the biogenetics feature from suspended phytoplankton.

參考文獻

Baker, J.E., Eisenreich, S.J., and Eadie, B.J., (1991). Sediment trap fluxes and benthic recycling of organic carbon, polycyclic aromatic hydrocarbons, and polychlorobiphenyl congeners in Lake Superior. Environmental Science and Technology. 25, 500-509.

Brincat, D., Yamada, K., Ishiwatari, R., Uemura, H., Naraoka, H., (2000), Molecular-isotopic stratigraphy of long-chain n-alkanes in Lake Baikal Holocene and glacial age sediments, Organic Geochemistry, 31. 287–294.

Chang, S.P., and Wen, C.G., 1997. Changes in water quality in the newly impounded subtropical Feitsui reservoir, Taiwan, Journal of the americal water resources association, 33. 343-357.

Doskey, Paul V., (2001), Spatial Variation and Chronologies of Alighatic Hydrocarbons in Lake Michigan Sediment. Environmental Science & Technology, 35, 247-254.

Effler, S.W., Matthews, D.A., and Kaser, J.W., Prestigiacomo, A.R., and Smith, D.G., 2006. Runoff event impacts on a water supply reservoir suspended sediment loading, turbid plume behavior, and sediment deposition. Journal of the American Water Resource Association. 42, 1697-1710.