Phosphorus Flux of Reservoir Sediments-- Hsin-Shan and Shih-man Reservoir

磷（Phosphorus）是許多水生生物之營養鹽限制因子，當水中磷濃度過高時會造成藻類大量生長使水體優養化，因此研究水庫中之內、外部磷負荷是維持良好水質之重要方法。許多研究證實，底泥是水庫內部磷之源（Source）與匯（Sink），故本論文以新山及石門水庫為研究對象，探討底泥磷釋出通量及其影響因子。 以磷之序列分選技術對上層10公分底泥及沈降物進行分析得知，新山水庫底泥磷組成主要為有機磷，約佔總磷量之96%以上。石門水庫底泥磷組成以鈣結合磷為大宗，約佔總磷量之78%。由於新山水庫底泥含多量之鐵金屬，溶氧之程度會影響鐵之氧化還原狀態，進而控制底泥磷之釋出。石門水庫底泥含鈣、鋁金屬，因此底泥磷之釋出不受溶氧之影響。新山水庫由沈降物捕集器所收集之總磷沈降通量約為1.36至1.68 mg/m2/day，石門水庫約為6.04 mg/m2/day，石門水庫支沈降量顯然受到外來來源之影響甚鉅。 透過好氧與厭氧之磷釋出通量試驗得知，新山水庫底泥在好氧時磷釋出通量約為0.10 mg/m2/day，厭氧約為3.57 mg/m2/day。石門水庫底泥好氧釋出通量約為0.13 mg/m2/day，厭氧約為0.10 mg/m2/day。經水庫磷質量平衡計算，新山水庫之底泥磷釋出於2006年超越水庫水體外部磷負荷量，石門水庫僅佔外部負荷之1.7%。因此可推測底泥磷對新山水庫具有相當程度之影響，相對而言，石門水庫之底泥磷釋出量對水體水質影響程度甚微。It has been demonstrated that phosphorus concentration is a limiting factor for the growth of planktons in reservoirs and lakes. High phosphorus concentration results in high rate of algae growth and eutrophic state of reservoirs. Bottom sediments have been identified as potential sink and source of phosphorus to the overlaying water. As a result, the understanding of the mechanisms and factors controlling phosphorus release flux from benthic sediment is needed. In the thesis, Hsin-shan Reservoir and Shih-men Reservoir were taken as our study sites for the investigation of sediment-water column interaction. The results of fractional extraction analysis of bottom sediments and settling matters show that organic-P and calcium-P dominate in Hsin-shan Reservoir and Shih-men Reservoir, respectively. Therefore, in Hsin-shan Reservoir, dissolved oxygen has great influence on the release of phosphorus from sediments because of its rich of ferric content in sediment. In contrast, in Shih-men Reservoir, dissolved oxygen may not affect the release of phosphorus since aluminum and calcium minerals dominate in sediment. Flux of total settling phosphorus collected by sediment traps ranged from 1.36 to 1.68 mg/m2/day in Hsin-shan Reservoir and 6.04 mg/m2/day in Shih-men Reservoir. For the reason above, settling flux in Shih-men Reservoir is influenced by external input significantly. Through the investigation of the phosphorus release flux under oxic or anoxic condition, the following results were observed: The release flux in oxic condition was about 0.10 and 0.13 mg/m2/day in Hsin-shan Reservoir and Shih-men Reservoir, respectively. Under anoxic condition, it was about 3.57 and 0.10 mg/m2/day in Hsin-shan Reservoir and Shih-men Reservoir, respectively. Mass balance for the annual external and internal phosphorus loading shows that released internal loading from bottom sediment has exceeded external loading in Hsin-shan Reservoir in 2006. However, internal phosphorus loading only accounts for 1.7% of the external loading in Shih-men Reservoir in the same year. So it is concluded that internal loading from sediments may have considerable impact on water quality in Hsin-shan Reservoir but minor impact in Shih-men Reservoir.中文摘要…………………………………………………………………………...Ⅰ 英文摘要…………………………………………………………………………...Ⅱ 目錄………………………………………………………………..………………..Ⅳ 表目錄……………………………………………………………………………...Ⅶ 圖目錄……………………………………………………………………………...Ⅷ 第一章 前言…………...……………………………………………………………1 第二章 研究背景與文獻回顧 ………………………………………………….3 2.1 水庫中之磷……………………………………………………………………….3 2.1.1. 水庫中磷之種類與來源……………………………………………….3 2.1.2. 底泥來源……………………………………………………………….4 2.2. 磷在水庫中之循環………………………………………………………………5 2.2.1. 磷在水體中之循環…………………………………………………….5 2.2.2. 磷在底泥中之循環…………………………………………………….5 2.3. 底泥磷釋出機制…………………………………………………………………7 2.3.1. 底泥磷移動化之影響因子…………………………………………….7 2.3.1.1. 底泥磷之組成………………………………………………..7 2.3.1.2. 氧化還原狀態………………………………………………..8 2.3.1.3. pH…………………………………………………………....10 2.3.1.4. 微生物礦化作用…………………………………………….11 2.3.1.5. 溶解與沈澱之平衡………………………………………….12 2.3.1.6. 吸附╱脫附作用………………………………………… 13 2.3.2. 底泥磷遷移之機制……………………………………………………14 2.3.2.1. 擴散作用…………………………………………………….14 2.3.2.2. 氣體對流………………………………………..………...…14 2.4. 磷的序列分選…………………………………………………………………...15 2.4.1. 磷的序列分選之發展…………………………………………………15 2.5. 底泥磷傳輸通量模式…………………………………………………………...17 2.5.1. 底泥磷模式發展………………………………………….…………...17 第三章 材料與方法……………………………………………………………...20 3.1. 研究流程…………………………………………………………..……………20 3.2. 研究場址背景…………………………………………………………………...21 3.2.1. 新山水庫………………………………………………………………21 3.2.2. 石門水庫………………………………………………………………21 3.3. 採樣方法………………………………………………………………………...23 3.3.1. 底泥採樣………………………………………………………………23 3.3.1.1. 底泥採樣方法……………………………………………….23 3.3.1.2. 底泥運送及保存方法……………………………………….23 3.3.2. 沈降物捕集方法………………………………………………………24 3.3.2.1. 沈降物捕集設備…………………………………………….24 3.3.2.2. 沈降物運送及保存方法…………………………………….24 3.4. 分析方法………………………………………………………………………...25 3.4.1. 底泥分析………………………………………………………………25 3.4.1.1. 底泥分析項目……………………………………………….25 3.4.1.2. 底泥分析方法……………………………………………….26 3.4.2. 沈降物分析……………………………………………………………28 3.4.2.1 沈降物分析項目……………………………………………..28 3.4.2.2. 沈降物分析方法…………………………………………….28 3.5. 底泥管柱磷釋出試驗…………………………………………………………...28 3.5.1. 底泥磷釋出試驗設備…………………………………………………28 3.5.2. 底泥磷釋出試驗分析項目及方法……………………………………29 3.6. 底泥磷通量模式之建立………………………………………………………...30 3.6.1. 概念模式………………………………………………………………30 3.6.2. 基本假設………………………………………………………………31 3.6.3. 方程式推導…………………………………………………………...32 第四章 結果與討論……………………………………………………………...35 4.1. 底泥分析結果…………………………………………………………………..35 4.1.1. 底泥總磷及孔隙水總磷、反應性磷………………………………...35 4.1.2. 底泥有機碳…………………………………………………………...37 4.1.3. 底泥金屬……………………………………………………………...38 4.1.4. 底泥凱式氮…………………………………………………………...42 4.1.5. 序列分選磷…………………………………………………………...44 4.1.6. 底泥粒徑分布………………………………………………………...47 4.1.7. 水質數據……………………………………………………………...49 4.2. 沈降物捕集器試驗結果………………………………………………………..54 4.2.1. 沈降物沈積量………………………………………………………...54 4.2.2. 沈降物總磷…………………………………………………………...55 4.2.3. 沈降物有機碳………………………………………………………...57 4.2.4. 沈降物序列分選磷…………………………………………………...57 4.3. 底泥磷釋出通量結果…………………………………………………………..58 4.4. 水庫內磷負荷推估……………………………………………………………..63 4.4.1. 新山水庫……………………………………………………………...63 4.4.2. 石門水庫……………………………………………………………...63 4.5. 釋出通量模式之模擬結果……………………………………………………..64 4.5.1. 表層水溶解總磷校正結果…………………………………………...64 第五章 結論與建議……………………………………………………………..67 5.1. 結論……………………………………………………………………………..67 5.2. 建議……………………………………………………………………………..69 參考文獻…………………………………………………………………………..7