劉振宇臺灣大學：生物環境系統工程學研究所盧光亮Lu, Kuang-LiangKuang-LiangLu2007-11-272018-06-292007-11-272018-06-292007http://ntur.lib.ntu.edu.tw//handle/246246/56003本研究針對濁水溪沖積扇南翼包括扇央及扇尾部分岩心之樣本進行分析，樣本為有機質豐富之細沙、泥或黏土等，由XRD之分析指出，其成份以二氧化矽及綠泥石等黏土礦物為主。其中平均砷含量高達62.35 mg/kg，而阻水層岩心中砷濃度略高於含水層，主要集中於鐵及矽酸鹽相，約佔總量80%以上。由XRF之資料顯示，砷之分布與鐵之(氫)氧化物及鐵硫化合物有關，與矽化合物應無較大之關聯性，於XPS之分析得知，鐵化合物應以無晶型之(氫)氧化鐵為主，也可能為還原溶解之釋出機制中砷之主要來源。地下水以Ca-Na-HCO3型態為主，砷濃度範圍從0.02~0.57mg/L，平均值為0.17 mg/L，皆大於飲用水標準(0.01 mg/L)。於扇央與扇尾皆監測出高砷濃度之地下水，而地下水中砷濃度與HCO3- 及NH4+之相關性佳，但與TOC及鈣離子之關係較差，顯示有機質參與反應，其主要之作用為增加地下水之碳酸根及氨氮離子濃度，使得地下水越趨於還原狀態。本區地層中砷之可能釋出機制，應與無晶型之鐵(氫)氧化物還原溶解有關，且碳酸根之取代也是主要反應之一。This study focused on the analysis of arsenic contents in sediments of the mid-fan and distal-fan of the southern Chou-Shui river alluvial fan. Core samples consisted of silly sand, mud and clay. SiO2 and chrolite were identified as the main components in the core samples by XRD. The average arsenic concentration of core samples is up to 62.35 mg/kg. The arsenic content in aquitards is slightly higher than that in aquifers, and is concentrated in the sequential extraction step of Fe and silicate phases, more than 80% of all the samples. The results from XRF revealed that the arsenic distribution correlates well with iron (oxy)hydroxide and arsenic-bearing pyrite, but poorly correlates with silicate. The main form of iron was amorphous (oxy)hydroxide according to the analysis of XPS and could be the main source of the reduction dissolution mechanism. The groundwater is generally Ca-Na-HCO3 type, with HCO3- as the principle anion. Total arsenic concentrations in the analyzed wells vary between 0.02 and 0.57 mg/L, and are higher than the drinking water standard (0.01mg/L). Arsenic concentrations correlated well with HCO3- and NH4+ contents, but less correlated with TOC and calcium contents. The reaction with organic matters which yields an increase of the concentrations of HCO3- and NH4+ may drive the groundwater toward a more reductive condition. Reductive Fe (oxy)hydroxide is envisaged as the main mechanism for the release of As into groundwater in our study region. Moreover, the replacement of carbonate ion would be another possible mechanism of As release to groundwater.目錄 誌謝 i 中文摘要 ii Abstract iii 目錄 iv 圖目錄 vi 表目錄 x 第一章 前言 1 1-1 研究動機 1 1-2 研究目的 2 1-3 論文架構 2 第二章 文獻回顧 3 2-1地層環境中砷之分布 3 2-1-1 全球總砷分布概述 3 2-1-2 孟加拉地區 4 2-1-3 台灣地區 5 2-2 地質環境中砷可能之釋出機制 5 2-3 礦物表面分析 7 2-4 連續萃取法 8 第三章 材料與方法 14 3-1 研究區域 14 3-2進行步驟 15 3-3 研究方法 16 3-3-1 樣本採集 16 3-3-2礦物分析之儀器型號與規格 16 3-3-3 礦物主成分及表面化學分析 17 3-3-4 連續萃取法實驗藥品 19 3-3-5連續萃取方法及步驟 19 第四章 結果與討論 29 4-1水文地質特徵、礦物主成分與地下水水質 29 4-1-1 水文地質特徵與礦物主成分 29 4-1-2 地下水水質 30 4-2 表面化學分析 32 4-2-1高解析電子能譜儀(HR-XPS) 32 4-2-2掃描式電子顯微鏡暨能量分散光譜儀(SEM-EDS) 34 4-3 連續萃取液總砷分析 35 4-4地質環境中砷之可能分布與釋出機制探討 36 4-4-1 地質環境中砷之可能分布 36 4-4-2地質環境中砷之可能釋出機制 38 第五章 結論與建議 75 5-1 結論 75 5-2 建議 76 參考文獻 775446550 bytesapplication/pdfen-US砷XPS釋出濁水溪沖積扇地下水arsenicreleaseChouShui River alluvial fangroundwaterthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/56003/1/ntu-96-R93622022-1.pdf