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年度	103	專案性質	實驗性質
專案類別	研究專案	研究主題	底泥
申請機構	國立台灣大學	申請系所	生物環境系統工程學系
專案主持人	張尊國	職等/職稱	教授
專案中文名稱	北投溫泉磺港溪不同粒徑底泥砷的分佈型態之研究
中文關鍵字	底泥；砷；逐級萃取；X-光繞射分析
專案英文名稱	Study the characteristics of As in sediments with different size fraction from Hot Spring Area of Huang Gang Creek, Beitou
英文關鍵字	Sediment；Arsenic；Sequential Extraction；XRD
執行金額
執行期間	2013/11/25 至 2014/11/24
計畫中文摘要	地熱谷溫泉形成於 18 萬年前，至今每天仍然有 2,000 噸含高礦物成分之溫 泉水排出，導致在磺港溪河道底泥中因結晶、吸附等形成許多富含砷的沉積 物。本研究的目的係針對磺港溪之沉積物中不同粒徑底泥透過連續逐級萃取 程序(SEP)的定量方法說明砷的移動狀況及釋出機制，並進一步解釋其型態 分布與鍵結狀況，以評估底泥中砷污染程度與對周遭環境的影響。本研究將 底泥通過五種不同尺寸的篩號，分別為 16 號(1.19 mm)、20 號(0.84 mm)、 100 號(0.15 mm)、200 號(0.075 mm)、300 號(0.05 mm)，藉由代表不同化學 性質的萃取條件，研析底泥重金屬砷型態分佈之吸附過程，依序為非特定吸 附態、特定吸附態、弱結晶鐵、鋁氧化物態、強結晶鐵、鋁氧化物態與殘餘 型態。結果顯示磺港溪之底泥型態以弱結晶鐵、鋁氧化物態、強結晶鐵、鋁 氧化物態與特定吸附態所佔比例較高，同時底泥中粒徑越小的顆粒所含的總 砷濃度也越高。而其非特定吸附態(<10%)及殘餘態(<3%)所佔比例較其他三 者低。本研究在分析逐級萃取所得之個別萃取階段資料發現，底泥粒徑越小 的顆粒所含砷濃度也越高的現象出現差異化，在粒徑由介於 0.075~0.05 mm 轉變成小於 0.05 mm 時，砷濃度值反而下降，其中以殘餘態(F5)最明顯。逐 級萃取程序有助於理解受污染農地及土壤中重金屬的型態分佈、移動狀況及 釋出機制，以評估土壤污染程度與影響。
計畫英文摘要	The hot spring at Geothermal Valley was took place 180,000 years ago and the discharge of more than 2,000 tons hot spring daily containing highly mineral substance has led to the rich lead and arsenic sediments via crystallizing and adsorbing in Huang Gang Creek up to present. The objective of this study is to investigate the distribution of arsenic concentrations by using the sequential extraction procedure(SEP) in the different particles-size sediments of Huang Gang creek. Prior to analysis, sediment samples were collected along the creek and sieved to fine-grained fractions: 1.19-0.84 mm, 0.84-0.15 mm, 0.15-0.075 mm, 0.075-0.05 mm and <0.05 mm in order to analyze the processes absorbed by arsenic via the different extraction conditions in chemistry. The SEP could obtain five chemical fractionations: the non-specifically sorbed, specifically-sorbed, amorphous and poorly-crystalline hydrous oxides of Fe and Al, well-crystallized hydrous oxides of Fe and Al, and residual phases. The results show that amorphous and poorly-crystalline hydrous oxides of Fe and Al, well-crystallized hydrous oxides of Fe and Al and specifically-sorbed were in the ascendant; in the meanwhile, finer grained sediment samples tend to have higher concentrations of As. Conversely, the percentage of the non-specifically sorbed(<10%) and residual phases(<3%) was lower than theirs. The study indicated that finer grained sediment samples don’t tend to have higher concentrations of As under considering each step of SEP. in other words, arsenic concentrations decreased in the particles-size sediment from 0.075-0.05 mm to <0.05 mm, especially for residual phases. Performing a SEP can target all potential primary chemical forms of arsenic in the soil solid phase, provide useful information to explain the agricultural land and soil heavy metal contamination, and then propose countermeasures.