劉振宇Liu, Chen-Wuing臺灣大學:生物環境系統工程學研究所吳明哲Wu, Ming-CheMing-CheWu2010-05-052018-06-292010-05-052018-06-292008U0001-2907200811104200http://ntur.lib.ntu.edu.tw//handle/246246/181134砷(Arsenic)為一種類金屬(metalloid)普遍存在於地球之地殼中，台灣的蘭陽平原有高濃度的砷存在於地下水中(平均0.091 mg/L)。本研究對蘭陽平原的29口地下水監測井之水質檢測資料，應用統計的因子分析法判斷主要造成地下水中砷濃度高的因子，且使用PHREEQC計算地下水平衡狀態下物種生成及飽和指數，再採取9口地質鑽探井共403個岩心樣本，分析岩心中的總砷與總鐵濃度，由地下水中含高砷濃度監測井中選取19和9個岩心土壤樣本，分別進行連續萃取、礦物主成分及表面分析，礦物主成分及表面分析是利用X光螢光分析儀(XRF)、高解析電子能譜儀(XPS)和電子顯微鏡暨能量分散光譜儀(SEM-EDS)。因子分析結果顯示，在淺層地下水中砷濃度主要受到土地利用汙染入滲引發還原作用所致，而深層地下水砷濃度主要為還原環境由沉積物中釋出。在岩心結果總砷與總鐵於海相沉積環境有相關性，而在非海相沉積環境皆無關，高解析電子能譜儀進一步分析鐵的成分指出海相沉積岩心以FeOOH、FeO與Fe3O4為主，且FeS出現在較下游處與PHREEQC計算結果一致。當地下水系統趨於還原時，造成原本吸附於顆粒表面之鐵(氫)氧化物便開始溶於地下水中，並釋放Fe(Ⅱ)，與原本吸附於鐵(氫)氧化物表面之As(Ⅲ)與As(V)離子，推測為蘭陽平原地下水中砷濃度的主要來源。Arsenic (As) is an ubiquitous metalloid in crust of the earth. High arsenic concentrations (average 0.091 mg/L) of groundwater were found in Lanyang plain of Taiwan. Groundwater from 29 wells was sampled and 14 hydro-geochemical parameters were analyzed. Factor analysis was applied to determine major influence factors of the arsenic, and PHREEQC was used to calculate the distribution of aqueous species and saturation index of which affected groundwater quality. 403 geological core samples from 9 drilling wells were collected and analyzed the contents of total arsenic and iron. Meanwhile, 19 and 9 core samples around high arsenic concentration groundwater were selected, respectively, for additionally sequential extraction and mineralogical phases analyzes, using x-ray fluorescence (XRF), high resolution x-ray photoelectron (XPS) and scanning electron microscope and energy dispersive spectrometer (SEM-EDS). Results of the arsenic-pollution factor determined by factor analysis indicated that infiltration of the pollutants from human activities to shallow groundwater, and the reductive dissolution from iron oxyhydroxides in the deep aquifer were the main processes of arsenic release to groundwater from the sediment. Total arsenic and iron contents of the core samples were well correlated in marine sequences. Surface analyses of core sample performed by XPS shown that arsenic was adsorbed copricipitated with noncrystalline iron oxyhdroxides. After a long term burial of sediment, microbial metabolism of organic matter creates a more reducing environment, arsenic may then be gradually released from iron oxyhydroxides by reductive dissolution or desorption to aqueous phase. Reduction dissolution or desorption of As from iron oxyhdroxides is considered as the most likely release process to groundwater in the Lanyang plain.摘要 ibstract ii錄 iv目錄 vii目錄 ix一章 緒論 1-1 研究動機 1-2 研究目的 2-3 論文架構 3二章 文獻回顧 4-1 地層環境中砷之分布 4-1-1 砷之基本化學及特性 4-1-2 砷之全球分布 6-1-3 台灣地區 7-1-4 地質環境中砷特徵與可能之釋出機制 8-2 因子分析 9-3 礦物表面分析 10-3-1 砷在土壤中的吸附 102-3-2 鐵氧化物表面化學特性 10-3-3 碳酸鹽礦物吸附特性 11-4 連續萃取法 11三章 材料與方法 13-1 研究區域 13-2 研究材料 15-3 水質特性分析 19-3-1 因子分析 19-3-2 派博水質圖法 19-4 岩心特性 20-4-1 總砷總鐵分析 20-4-2 礦物成分與表面化學分析 21-4-3 連續萃取分析 22-5 地下水水質之物種生成與飽和指數計算 25四章 結果與討論 26-1地下水水質因子特性分析 26-1-1 水質化學特性 26-1-2 因子分析 33-1-3 地下水物種砷分布 37-2礦物主成分(XRF)與地質特徵 40-3表面化學分析 45-3-1 高解析電子能譜儀(HR-XPS) 454-3-2 掃描式電子顯微鏡(SEM) 47-4連續萃取總砷分析 53-5 地化模擬(PHREEQC) 55-6 綜合討論 60-6-1 地質環境中砷之分布與特徵 60-6-2 砷之釋出機制 61五章 結論與建議 63-1 結論 63-2 建議 65考文獻 66錄：蘭陽平原岩心總砷與總鐵檢測結果 75application/pdf4110959 bytesapplication/pdfen-US砷因子分析蘭陽平原地球化學模式連續萃取X光螢光分析儀高解析電子能譜儀掃描式電子顯微鏡暨能量分散光譜儀ArsenicFactor analysisLanyang plainGeochemical modellingsequential extractionX-ray fluorescence(XRF)High resolution x-ray photoelectron spectrometer(XPS)Scanning electron microscope and energy dispersive spectrometer(SEM-EDS)[SDGs]SDG14thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/181134/1/ntu-97-R95622043-1.pdf