The Influence of Iron Ion on Chemical Coagulation and Sludge Dewatering for Tannery Wastewater
林孟憲、魏漣邦
E-mail: [email protected]
ABSTRACT
ABSTRACT In this study, pH adjustment, and chemical coagulation by polyaluminum chloride (PAC) and ferric chloride to remove suspended solid and COD in wet blue tannery wastewater were explored; and the settleability and dewatering characteristics of ferric and aluminiferous sludge were tested. The study can be concluded as follows: (1) without coagulation, the pH adjustment (below 3, or above 11) can remove SS and COD effectively, (2) removal for ferric chloride below 30mg/l rather than PAC below 30mg/l could remove SS and COD more effectively, (3) chemical coagulation with PAC and ferric chloride would be more efficient to remove SS and COD than with PAC alone, (4) seguential coagulation would be conducive to remove COD, (5) coagulation with PAC and ferric chloride would increase the settleability of flocs, and (6) the dewatering of ferric sludge would be better than that of aluminiferous sludge, so the addition of ferric chloride would improve the dewatering of Al sludge. Key Words : Tannery
wastewater, Chemical coagulation, Dual coagulation, Sludge dewatering, Ferric Chloride.
Keywords : Tannery wastewater ; Chemical coagulation ; Dual coagulation ; Sludge dewatering ; Ferric Chloride Table of Contents
目錄 第一章 緒言 1.1 研究緣起………..……….1 1.2 研究目的………
…..……….1 1.3 研究內容………..……….2 第二章 文獻回顧 2.1 水解混凝劑………
……….….…….3 2.1.1 Al(III)和Fe(III)的單體水解產物………….……3 2.1.2 Al(III)和Fe(III)的多核物種….………...….…
…6 2.2 混凝的機制……….……….………...….….9 2.2.1 電雙層壓縮………..………….….9 2.2.2 吸 附及電性中和………..………....11 2.2.3 沈澱絆除……….…...….11 2.2.4 吸附及架橋作用…
……….……....13 2.2.5 溶解性有機物與膠體顆粒去除機制…….…....14 2.3 混凝影響因素………...……
….…………....15 2.3.1 鹼度/pH的影響……….………….16 2.3.2 陰離子的影響……….…...…….17 2.3.3 溶解有機物的作用………...….…….18 2.3.4 其他影響………...………….………….…20 2.4 污泥脫水……
………..………...20 2.4.1 膠羽組成簡介………..………20 2.4.2 脫水性指標………
…………..………22 2.4.3 顆粒分佈和顆粒大小………..…………....23 2.4.4 膠羽密度………...………..……
…….24 2.4.5 無機混凝劑的化學特性…………..………...25 第三章 實驗材料與方法 3.1 實驗流程………
……..……..……….26 3.2 實驗設備………..…..…….29 3.3 實驗藥品………
…..…..……….29 3.3.1 混凝劑…………..………..…..………29 3.3.2 pH調整劑………..…………..…………
….30 3.3.3 實驗廢水備製………..…………30 3.4 實驗步驟………..………...30 3.4.1 實驗廢水單純調整pH值， 對SS與COD之影響實驗………...…...30 3.4.2 瓶杯試驗……….….…….…….
…..31 3.4.3 二個混凝程序混凝實驗……….….…..…..32 3.4.4 沈降性實驗……….….…...….33 3.4.5 污泥 脫水指標實驗……….….…..…..34 第四章 結果與討論 4.1 廢水特性…….………..…..……35 4.2 原廢水調整pH...36 4.2.1 原廢水在酸性狀況下的影響………..…....…....36 4.2.2 原廢水在鹼性狀況下的影 響………...…..….…38 4.2.3 pH值對原廢水的影響……….………..…..39 4.3 化學混凝實驗...41 4.3.1 聚 氯化鋁的混凝……….……....…….41 4.3.2 氯化鐵的混凝………..………..……..44 4.3.3 氯化鐵與聚氯化鋁 的混凝…………..…...…….45 4.3.4 二個混凝程序混凝………..……...50 4.4 沈降性實驗………
…..…………...52 4.4.1 鋁污泥的沈降性………..……...52 4.4.2 鐵污泥的沈降性………....……...54 4.4.3 鋁、鐵污泥的沈降性比較………...55 4.5 污泥脫水實驗………..………...57 4.5.1 鋁污 泥的脫水指標實驗………..……....58 4.5.2 鐵污泥的脫水指標實驗………..……....59 4.5.3 鐵與鋁污泥的脫水指 標實驗…………..……....60 4.6 綜合評估……….62 第五章 結論與建議 5.1 結論………
………..……...…63 5.2 建議………..………...64 參考文獻………
………..………..…65 附錄一 製革及皮革廢水簡介………..……..…..72 附1.1 製革簡介
………..…………..72 附1.1.1 一般製革方法………..…..……….…73 附1.1.2濕藍皮(wet blue)製程…
………..…..……..78 附1.2 皮革廢水特性簡介………..……..……80 圖目錄 圖2.1 基本水合層與二級水合層………
………..……….………4 圖2.2無定形氫氧化物平衡的Fe(III)和Al(III) 單體水解產物濃度………..
…...5 圖2.3 Fe鹽與Al鹽水解產物與無定形氫氧化物平衡圖………6 圖2.4 keggin的結構圖………..………
………..…...….7 圖2.5 鋁鹽溶液中和滴定曲線， 添加鹼B(OH/Al)與pH值變化………..8 圖2.6在 水中鋁物種與 最初攜帶負電荷的顆粒交互作用示意圖………...………...12 圖2.7 鐵、鋁鹽掃曳混凝設計操作圖………
……….13 圖2.8 混凝反應概念……….………...15 圖2.9 污泥膠羽的三個基本單位結構
……….………...22 圖3.1 瓶杯試驗實驗流程…..……….……….26 圖3.2 沈洚性實驗流程…
……….………...27 圖3.3 污泥脫水實驗流程……….…………...28 圖4.1 酸性pH 值之SS、COD去除率……….………....37 圖4.2 鹼性pH值之SS、COD去除率……….………....39 圖4.3 極端pH值之SS、COD去除率...41 圖4.4 聚氯化鋁加藥量與SS、COD去除率之關係……….
…….…..43 圖4.5 聚氯化鋁加藥量與pH之關係……….….……...43 圖4.6 氯化鐵加藥量與SS、COD去除率之關 係………..……….…..45 圖4.7 氯化鐵加藥量與pH之關係………..….…….…...45 圖4.8 固定PAC 50mg/l，添加氯 化鐵與SS、COD去除率之關係…..47 圖4.9 固定PAC 50mg/l，添加氯化鐵與pH之關係………...47 圖4.10 固定PAC 30mg/l，添加氯化鐵與SS、COD去除率之關係...48 圖4.11 固定PAC 30mg/l，添加氯化鐵與pH之關係……….48 圖4.12 固定質量濃度之鐵、鋁鹽化學混凝SS、COD去除率…..…49 圖4.13 固定質量濃度之鐵、鋁鹽加藥量與pH之關係…
………….50 圖4.14 鋁污泥沈降性實驗………..……….53 圖4.15 PAC加藥量與污泥體積之關係……
……….……..…53 圖4.16 鐵污泥沈降性實驗……….….…….55 圖4.17 FeCl3加藥量與污泥體 積之關係………....……..55 圖4.18 鋁、鐵污泥沈降性實驗比較………....………....57 圖4.19 鐵、鋁鹽 加藥量與污泥體積之關係……….…..….57 圖4.20 鋁污泥的污泥脫水指標實驗結果……….….….…59 圖4.21 鐵污泥的污泥脫水指標實驗結果………..…….…60 圖4.22 鐵鋁污泥的污泥脫水指標實驗結果……….
….….…61 附圖1.1 單寧鞣革流程圖……….….….…..76 附圖1.2 鉻鞣革流程圖………
…………...………..77 附圖1.3 濕藍皮製程流程圖………...………..79 表目錄 表4.1 實驗廢水基本性質…
………..…………...36 表4.2 鋁鹽混凝的二次混凝………..………...51 表4.3 鐵鹽混凝 的二次混凝……….51 表4.4 鐵鋁鹽混凝的二次混凝………..………...51 表4.1 鐵鋁污泥CST數據……….……...62 附表1.1 一般典型製革廠廢水來源及特性……….
….….…..81 附表1.2 鹽漬牛皮製革廢水污染來源及特性……….….….…..83 附表1.3 濕藍皮製革廢水來源及特性………
……….….….…..84 附表1.4 文獻中皮革廢水特性……….………..…….….85 REFERENCES
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