67 research outputs found
Illite, Vermiculite and Montmorillonite of 2:1 Clay Minerals Related to Shale Classifications and KCI muds
No full textDistribution of 137Cs in temperate forest ecosystem after forest fire in central Taiwan.
No full textTransportation of Cesium and Strontium in Soils Nearby Nuclear Facilities
No full text污染土壤中放射性核種的來源可能來自核子試爆後大氣沉降、核燃料操作過程的疏失，例如蒸發池、液態儲存槽、掩埋場的洩漏，或是核能生產過程中意外的洩漏或釋出。如果棄置不顧，這些污染土壤不但將立即危害人類健康而且會持續造成環境風險。因此環境中放射性核種的化學與生物交互作用將變的相當重要。本研究目的將針對鄰近核設施土壤中銫與鍶之遷移與轉化進行研究，其中包含銫和鍶吸附動力學、吸附能力、土壤中的傳輸、釋放機制以及評估油菜對銫累積的能力。
為了能夠清楚了解放射性核種外洩事故發生時，洩漏至土壤後，土壤對核種之緩衝之能力，因此分別選定具代表性之土壤進行研究。土壤採樣地點可分為四個地區，分別是鄰近核能研究所、鄰近第三核能發電廠、第一核能發電廠以及蘭嶼暫時貯存廠四個地區之土壤進行試驗。
實驗結果顯示在本研究中，短晶距三氧化物(尤其是與有機鍵結鐵鋁氧化物) 影響對銫和鍶的最大吸附量。根據所有方程式飾配結果，二級速率方程式具有較佳的擬合結果，因此本實驗中選用二級速率方程式來計算速率常數。土壤反應組成顯著的與銫和鍶的最大吸附量有關，也因此影響銫和鍶的動力吸附。
線性與非線性吸附參數導入Lt與Kt土壤中銫和鍶傳輸行為。 由統計分析結果，ARE、ME、RMSE及CV 值顯示MT3DMS 傳輸模式對銫和鍶在土柱中傳輸模擬良好。 最好的預測是由Freundlich 非線性遲滯因子。 應用Freundlich 非線性遲滯因子至一維延散擴散傳輸模式中能獲的良好的預測結果並能評估化合物在土註中傳輸的命運。
磷酸銨誘發137Cs 從污染土壤釋放的動力學可由 two-constant rate equation 描述。 由1 M NH4H2PO4 溶液(pH 4.0)造成污染土壤中137Cs 釋出的速率常數較1 M NaCl 溶液(pH 4.0)抽出高。 然而(NH4)2SO4 、NH4Cl及 KCl 溶液抽出卻有相同的趨勢。低分子量有機酸的分泌會增加氫離子濃度。 H+ 能質子化破烈邊緣的氫氧基及氧原子或是弱化礦物表面的 Mg-O, Fe-O, and Al-O 鍵。 低分子量有機酸是一種強力的錯合配位基，它能與礦物的 OH 及 OH2 基交換並與表面陽離子形成錯合如 Al、Fe及Mg。合併磷酸根與質子誘導效應是控制土壤黏土礦物中銫釋出制磷酸銨溶液中的主要機制。 施用磷酸銨肥料至土壤中會促進 137Cs 釋放並因此增加植物吸收、遷移至地下水以及進入食物鏈的機會。
Lt與Kt土壤中根圈土壤中低分子量有機酸總量與油菜中銫累積量有關。 Lt與Kt土壤影響油菜根圈中低分子量有機酸的量表示土壤中的化學及生物性質能控制根圈土壤有機酸的量與種類。 一般來說揮發性有機酸 (如乙酸、丙酸及丁酸) 的貢獻佔兩種土壤根圈總有機酸的67.8 % 至 87.3 %。 然而Kt根圈土壤中較Lt根圈土壤中有較高的有機酸含量。 更多的銫會從土壤中釋放並增加油菜對銫的吸收。 對於調控根-土壤動態機制的更進一步的研究是必要的並且可以降低放射性元素污染食物鏈。Abstract
Radionuclide-contaminated soils were contaminated either through accidental spillage or leakage, deposition of airborne material during nuclear testing and incinerator processing, or plume development from evaporation ponds, liquid-storage tanks, and burial grounds and, operation of nuclear facilities. If left untreated, these contaminated soils may represent not only an immediate danger to human health, but also a chronic environmental hazard. Therefore, it is very important for interacting between chemical and biological of radionuclide in the environment. These objectives are focusing on transportation and transformation of cesium and strontium in the soils nearby nuclear facility, including kinetics and isotherm of cesium and strontium, transportation in the soils, release mechanism, and capacity of cesium accumulation in the rape.
Soil sampling was separated to four sites, including Institute of Nuclear Energy Research, the Third Power Plant, the First Power Plant, and Lan-Yu Storage Plant.
The data indicate that among components of the subtropical and tropical soils studied, short-range ordered sesquioxides especially Al and Fe oxides complexed with organics play an important role in influencing their capacity and dynamics of Cs and Sr adsorption.
Both linear and nonlinear equilibrium-controlled sorption parameters were examined to describe the Cs+ and Sr2+ transport behavior in the red and iron-rich calcareous soils. From statistical analysis, the ARE, ME, RMSE and CV values revealed that MT3DMS simulated well with the Cs+ and Sr2+ transportation in soil column. The best predictions and measurements were obtained from Freundlich nonlinear retardation factors. Application of Freundlich nonlinear retardation factors to the one-dimensional advection-dispersion transport equation with an explicit.
The kinetics of the NH4H2PO4-induced 137Cs release from the contaminated soils can be described by a two-constant rate equation. The rate-coefficient values of 137Cs release from contaminated soil in 1 M NH4H2PO4 solution (pH 4.0) were much higher than that of the 1 M NaCl solution (pH 4.0). However, it showed a similar desorption trend in (NH4)2SO4 and NH4Cl, and KCl solutions. The combined effect of phosphate and proton was the major mechanism of 137Cs release from contaminated soils in NH4H2PO4 solution. Application of NH4H2PO4 fertilizer to soil is recommended to promote 137Cs release from soil, and thus also increase opportunity for plant uptake, migration to groundwater and entry into the food chain.
The amounts of LMWOAs present in the rhizosphere soils were co-related to Cs accumulation in rape grown in the Lt and Kt soils. Lt and Kt soils affected the total amount of LMWOAs exudates found in the rhizosphere soil of rape, indicating that chemical and biological properties of soils can alter the composition and quantity of organic acids in the rhizosphere soils. Generally, volatile acids (i. e. acetic, propionic, and butyric acids) contributed for 67.8 % to 87.3 % of the total LMWOAs in the rhizosphere of both soils. However, the Kt soil contains higher total LMWOAs in the rhizosphere soils than that of the Lt soil. More Cs was released from soils and led to increased Cs uptake by rape. Further understanding of the basic mechanisms regulating root-soil dynamics is essential for reducing the contamination of food chain with radioelements.中文摘要 --------------------------------------------------------------------------------------I
英文摘要 --------------------------------------------------------------------------------------III
目錄 --------------------------------------------------------------------------------------V
表目錄 -------------------------------------------------------------------------------------VII
圖目錄 ------------------------------------------------------------------------------------VIII
第一章 緒論---------------------------------------------------------------------------------1
第二章 臺灣核設施土壤銫和鍶等溫與動力吸附研究------------------------------8
2-1 前言----------------------------------------------------------------------8
2-2 材料與方法-----------------------------------------------------------10
2-2-1 研究區土壤----------------------------------------------------------10
2-2-2 化學分析-------------------------------------------------------------12
2-2-3 黏土礦物分析-------------------------------------------------------14
2-2-4 等溫吸附-------------------------------------------------------------14
2-2-5 動力吸附-------------------------------------------------------------15
2-2-6 放射性銫等溫吸附實驗-------------------------------------------16
2-2-7 137Cs活度測定-----------------------------------------------------16
2-2-8 統計分析-------------------------------------------------------------17
2-3 結果與討論---------------------------------------------------------17
2-5 結論------------------------------------------------------------------38
第三章 銫和鍶在鄰近核設施土壤之傳輸-------------------------------------------39
3-1 前言------------------------------------------------------------------39
3-2 模式描述------------------------------------------------------------40
3-2-1 Linear 等溫吸附-------------------------------------------------42
3-2-2 Langmuir等溫吸附----------------------------------------------42
3-2-3 Freundlich等溫吸附---------------------------------------------43
3-2-4 傳輸模式-----------------------------------------------------------43
3-3 材料與方法---------------------------------------------------------44
3-3-1 實驗室分析----------------------------------------------------------44
3-3-2 批次實驗-------------------------------------------------------------44
3-3-3 管柱實驗-------------------------------------------------------------44
3-3-4 MT3DMS 預測誤差分析-----------------------------------------47
3-4 結果與討論---------------------------------------------------------47
3-4-1 土壤性質-------------------------------------------------------------47
3-4-2 吸附-------------------------------------------------------------------50
3-4-3 傳輸-------------------------------------------------------------------52
3-5 結論------------------------------------------------------------------56
第四章 肥料溶液對污染土壤中放射性銫釋放動力學----------------------------57
4-1 前言------------------------------------------------------------------57
4-2 材料與方法---------------------------------------------------------58
4-2-1 研究區----------------------------------------------------------------58
4-2-2 土壤分析-------------------------------------------------------------58
4-2-3 污染土壤放射性銫釋放動力學----------------------------------59
4-2-4 更新肥料溶液對放射性銫釋放的影響-------------------------59
4-3 結果與討論---------------------------------------------------------59
4-3-1 土壤性質與污染土壤137Cs 釋出量----------------------------59
4-3-2 污染土壤中放射性銫釋放動力學-------------------------------62
4-3-3 肥料更新與 137Cs 釋出------------------------------------------66
4-3-4 銫釋放的機制-------------------------------------------------------68
4-4 結論------------------------------------------------------------------68
第五章 銫污染土壤中油菜(Brassica campestris)
根低分子量有機酸之分泌---------------------------------------------------70
5-1 前言------------------------------------------------------------------70
5-2 材料與方法---------------------------------------------------------------71
5-2-1 土壤採樣----------------------------------------------------------------71
5-2-2 油菜(Brassica campestris) 盆栽試驗----------------------------71
5-2-3 植體與土壤中之銫含量----------------------------------------------72
5-2-4 低分子量有機酸含量-------------------------------------------------72
5-2-5 統計分析----------------------------------------------------------------76
5-3 結果與討論---------------------------------------------------------------76
5-3-1 土壤物理化學特性----------------------------------------------------76
5-3-2 植體所吸收的銫-------------------------------------------------------77
5-3-3 根圈土壤低分子量有機酸 (LMWOAs) --------------------------83
5-4 結論------------------------------------------------------------------------87
第六章 總結----------------------------------------------------------------------------------88
第七章 參考文獻------------------------------------------------------------------------------89
表目錄
表2.1. 供試土壤物理性質------------------------------------------------------------------18
表2.2. 供試土壤化學性質------------------------------------------------------------------19
表2.3. 供試土壤三氧化物含量------------------------------------------------------------21
表2.4. 黏土礦物組成半定量分析---------------------------------------------------------23
表2.5. 土壤中銫和鍶等溫吸附參數------------------------------------------------------25
表2.6. 土壤中放射性銫吸附分配係數---------------------------------------------------27
表2.7. 土壤性質與最大吸附量之相關性------------------------------------------------29
表2.8. 反應過程中銫和鍶的吸附量------------------------------------------------------30
表2.9. 供試土壤銫吸附動力學之不同動力模式之r2、p及SE值-------------------33
表2.10. 供試土壤鍶吸附動力學之不同動力模式之r2、p及SE值------------------34
表2.11. 供試土壤銫和鍶吸附二級速率常數-------------------------------------------37
表3.1. 互溶性取代管柱實驗條件---------------------------------------------------------46
表3.2. 供試土壤物理化學性質-------------------------------------------------------------48
表3.3. 黏土礦物組成半定量分析---------------------------------------------------------49
表3.4. Lt和Kt土壤銫和鍶線性與非線性等溫吸附參數------------------------------51
表3.5. Lt與Kt土壤線性與非線性模式預測之平均相對誤差、最大
誤差、根均方誤差及變異係數------------------------------------------------------55
表4.1. 在0.083至4小時間不同肥料對污染土壤137Cs釋放動力
模式擬合程度比較-------------------------------------------------------------------64
表4.2. 在0.083至4小時間不同肥料對污染土壤137Cs釋放
two-constant速率常數--------------------------------------------------------------65
表5.1. 標準品低分子量有機酸之揮發性質、種類、化學式及中文名稱------------73
表5.2. 供試土壤物理化學性質------------------------------------------------------------78
表5.3. Lt及Kt土壤中施用不同濃度銫後油菜(a)根及(b)莖之生物累積量-------82
表5.4. Lt及Kt土壤施用不同銫濃度中油菜根圈土壤低分子量有機酸含量------85
圖目錄
圖1.1. 放射性核種釋放至環境中潛在傳輸途徑-----------------------------------------2
圖1.2. 雲母中銫和鉀陽離子契型固定位置-----------------------------------------------4
圖 2.1. 研究區域地理位置及採樣位置圖-----------------------------------------------11
圖2.2. 土壤對銫吸附動力學之二級速率方程式飾配圖。實驗條件
為1.0 g L-1 之土壤，pH 4.0，初始濃度CsCl 0.188 mM
，背景溶液為0.01 M NaCl。 快反應時間為前2-30分
鐘；慢反應為30-480分鐘--------------------------------------------------------32
圖2.3. 土壤對鍶吸附動力學之二級速率方程式飾配圖。實驗條件
為1.0 g L-1 之土壤，pH 4.0，初始濃度SrCl2 0.285 mM
，背景溶液為0.01 M NaCl。快反應時間為前2-30分鐘
；慢反應為30-480分鐘-----------------------------------------------------------36
圖3.1. (a)Lt與(b)Kt土壤之銫實驗與預測突破曲線-----------------------------------53
圖3.2. (a)Lt與(b)Kt土壤之鍶實驗與預測突破曲線-----------------------------------54
圖4.1. 1 M NH4H2PO4、0.5 M (NH4)2SO4、1 M NH4Cl、1 M KCl
及1 M NaCl溶液對土壤釋放137Cs(溫度25℃、反應48小時)------------61
圖4.2. (a) 1 M NH4H2PO4、(b) 0.5 M (NH4)2SO4、(c) 1 M NH4Cl
、(d) 1 M KCl及(e) 1 M NaCl 溶液對污染土壤中137Cs
脫附動力學之two-constant速率方程式飾配圖-----------------------------63
圖4.3. (a) 1 M NH4H2PO4、(b) 0.5 M (NH4)2SO4及(c) 1 M NH4Cl
肥料溶液更新對污染土壤釋放137Cs之影響---------------------------------67
圖5.1. 本體或根圈土壤低分子量有機酸的萃取及分析流程------------------------80
圖5.2. Lt與Kt土壤中油菜(a)根與(b)莖之乾重-----------------------------------------79
圖5.3. 在不同CsCl濃度下Lt與Kt土壤中油菜(a)根(b)莖及(c)整株銫累積量--80
圖5.4. Lt及Kt土壤中油菜(a)根及(b)莖中銫濃度-------------------------------81
圖5.5. Lt及Kt土壤中油菜根圈土壤總低分子量有機酸之分佈---------------------8
Low-molecular-weight Organic Acids and Metal Speciation in Rhizosphere and Bulk Soils of a Temperate Rain Forest in Chitou, Taiwan
No full textSynthesis and Structural Study of Zinc and Cadmium Thiolate Complexes with Sulfur Rich Coordination Environment
No full textWe have successfully synthesized the zinc and cadmium complexes containing bis(3-trimethylsilyl-2-thiophenyl)phenylphosphine (SiPS2): [NEt4][(SiPS2)Cd(SC6H5)] (1) , [NEt4][(SiPS2)Cd(SC6H11)] (2) , [NEt4][(SiPS2)Cd(SCH2C6H5)] (3) , [NEt4][(SiPS2)Zn(SC6H5)] (4) , [NEt4][(SiPS2)Zn(SC6H11)] (5) and [NEt4][(SiPS2)Zn(SCH2C6H5)] (6) , and characterized them using 31P NMR and mass spectrum.1 and 2 were also characterized by X-ray diffraction methods.
In the attemprs to get crystals of 4 and 6, we got the oxidized dimer complex 4* and 6* instead. In these complexes the two oxygen atoms of the oxidized ligands and the sulfur atom of the monodentate thiolate ligand bridge both the cadmium centers.
Zinc complexes exhibit distorted tetrahedral structure. However, the cadmium ion tends to form five coordination oxidation dimeric complexes
Effect of dissolved organic carbon (DOC) by different thinning intensities in temperate forest.
No full textSoil column leaching experiments with simulated acid rains fractions and heavy metals distribution of the Changhua contaminated soils in central Taiwan.
No full textSorption isotherms and kinetics of cesium and strontium sorbed by selected subtropical and tropical soils
No full text
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