• 作者： 洪佳章; 萬政康
• 作者服務機構： 國立中山大學海洋地質研究所
• 中文摘要： 本研究探討缺氧河川（急水溪）及河口中溶解態及顆粒態微量金屬元素之地化反應過程。資料顯示急水溪河川部份並無顯著微量金屬污染現象，然中下游有機質之污染卻相當嚴重。大量有機廢水注入河川末端及感潮上游地區，造成河口低鹽度地帶水體含有極高之溶解性有機碳、生化需氧量及嚴重缺氧狀態。大部份微量金屬及溶解性有機碳在低鹽度地帶發生明顯的去除及沈降作用。鐵、錳元素因受溶氧高低影響，在河口地區進行氧化還原的地化循環作用。銅、鎳以及顆粒態鉛、鋅在河口地區雖可能參與鐵、錳循環作用，然其分佈類似於有氧狀態河口之分佈狀態。溶解態鉛及鋅在河口地區可能形成硫化錯合物，導致其分佈與預期有所差異。由於豐、枯水期水量差異大，使得河口，尤其低鹽度地帶水體溶氧、pH值、及溶解性有機質含量明顯不同，因此造成豐、枯水期微量金屬溶解態、顆粒態及其化學相等分佈的差異，其中尤以氧化還原敏感的鐵、錳差異最大。利用箱形模式估算結果發現：溶解態及顆粒態錳以及溶解態鉛、鋅的河口淨輸出量高於其輸入量，溶解態鐵之輸出量遠低於其輸入量，而顆粒態鐵之輸出量約等於輸入量，另一方面溶解態及顆粒態銅、鎳以及顆粒態鉛、鋅則分別以不同比例的量沈降於河口中。
• 英文摘要： Geochemical processes of dissolved and particulate trace metals in an oxygen-deficient (Chishui)river and estuary were studied during the low-flow and high-flow seasons. Metal distribution displayed onlya slight increase but organic pollution in the middle and downstreams was very serious. Discharge oforganic sewage into the upper tidal region of the estuary resulted in esturarine water with depleteddissolved oxygen and very high concentrations of DOC and BOD. Most trace metals and DOC were signifi-cantly removed from the esturarine water in the low salinity region as riverwater, sewage and ocean watermixed together. Iron and manganese were subjected to redox fluctuations and recycled in the estuaryCopper and nickel as well as particulate lead and zinc were more likely to behave as in an aerobic estuaryeven though they might be involved in Fe-Mn cyclings. Dissolved lead and zinc, however, were apparentlydifferent from that in an aerobic estuary through formation of sulfide-containing complexes. Distributionsof trace metals, particularly for Fe and Mn in the dissolved and particulate phases as well as in the chemicalforms of solids in the estuary were different between low-flow and high-flow seasons, resultingfrom different conditions of dissolved oxygen, pH and dissolved organic matter. The modelled net fluxesof trace metals, therefore, show that Mn and dissolved Pb (Zn) were transported with excess to the grossinput, and particulate Fe was only slightly retained, but dissolved Fe was largely retained in the estuary.Dissolved Cu and Ni as well as particulate Cu, Ni, Pb and Zn were trapped in the estuary in various propor-tions due to their being less sensitive to redox change.
• 中文關鍵字： Behavior; dissolved; particulate; trace metals; oxygen-deficient; river; estuary
• 英文關鍵字： --