駱尚廉臺灣大學：環境工程學研究所許 惠 卿Hsu, Hsei-ChingHsei-ChingHsu2007-11-292018-06-282007-11-292018-06-282005http://ntur.lib.ntu.edu.tw//handle/246246/62728有鑑於半導體業中砷化鎵材料之興起，高濃度砷系廢水成為目前新興之污染物，砷已被證實和肺癌、肝癌及皮膚癌有關，濃度過高更會致人於死，因此，如何妥善處理此廢水是目前重要課題。 過去對砷之處理範疇，大多以低濃度為主，高濃度之研究較為有限，目前對於高濃度砷系廢水的處理，都是以鈣鹽固定為主，但是無法使廢水達到管制標準，需要再合併於其他程序進行處理，然砷酸鈣不易沉澱，污泥蒐集困難，砷污泥之處理費用更為一般污泥之五倍。因此本研究期望發展出一套可行又有效率之處理方法。 本研究主要結合鈣鹽沉降與電聚浮除法來處理500ppm之高濃度含砷廢水，就其可行性推估、主要去除機制、鈣鹽添加量、界面活性劑、電流密度、酸鹼度及干擾離子對除砷效率的影響進行探討。 實驗結果顯示，鈣鹽添加量對除砷效果有很大影響，當沒有添加鈣鹽對砷 僅有78.8%去除率，當添加鈣鹽，去除率可達99.9%，陰離子型界面活性劑(SDS)較有助於系統對膠羽之浮除，電流密度對砷之去除與浮除效果是重要操作因子，本研究之最佳操作條件為: 鈣鹽添加量=1.962g/L(Ca/As莫耳比=2)、SDS添加量=50mg/L、電流密度= 17.86mAcm-2、反應時間=15分鐘。在此操作條件下，殘餘砷濃度小於0.5ppm, SS小於30mg/L。 由酸鹼度影響實驗發現，最終pH對除砷效果較初始pH值重要。pH值改變也會造成顆粒表面界達電位改變，最佳浮除效果發生在零電位點，當廢水中存在陰離子，會與砷酸根離子競爭鈣鹽，及競爭SDS表面位置，整體來說影響之程度由大至小分別為：PO43-、SiO32-、SO42-、CO32-。Because gallium arsenide (GaAs) becomes a new material in the semiconductor industry, the problem of treating high-arsenic-containing wastewater has newly risen. Arsenic has already been proved to be in relation to lung cancer, liver cancer and skin cancer. Excessive uptake of arsenide will cause death. Therefore, treating arsenic wastewater well is an important issue for environmental engineers nowadays. The treatment of arsenic is mostly aimed at low-concentration in the past and the process for high-arsenic-containing wastewater is limited. A common method for removing arsenic from wastewater is principally in calcium precipitation. But the treatment of calcium precipitation cannot reach the discharge standards of wastewater. It therefore needs to combine with other processes. Moreover, the sludge of calcium arsenates is very difficult to precipitate and collect. The costs of arsenic sludge treatments are five times to the ones of the normal sludge. Therefore, this study expects to develop a feasible and effective method to remove arsenic in high-arsenic-containing wastewater. This study combined precipitation of calcium, and electro-coagulation- flotation to treat the wastewater with 500ppm of As. The effects of the additions of calcium, type and concentration of the surfactants, current densities, pH, and interference ions on arsenic removal efficiency were eximed. The results indicated that the additions of calcium dramatically influenced the efficiency of arsenic removal. The removal efficiency increased from 78.8% to 99.9% as calcium was added. SDS facilitated to flotation efficiency. The current density is an important operating factor influencing arsenic removal and flotation efficiency. The best operating system of this study was the following, the dosages of calcium =1.962g/L(Ca/As molar ratio=2), the additions of SDS=50mg/L, the current density= 17.86mAcm-2, the reaction time=15 minutes. Under this operating system, the residual concentration of arsenic was less than 0.5ppm and SS was less than 30mg/L in the effluent. The final pH is more important than initial pH for arsenic removal. The changes of pH value caused the changes of zeta potential of particles. The optimum flotation efficiency occurs at the zero point of surface charged. The co-existing of anions compete the calcium with arsenate and the active cites with SDS. This fact cause the decrease the efficiencies of arsenic removal and SS removal. The series of the influence is PO43- > SiO32- > SO42- > CO32-.中文摘要 I Abstract II 目錄 IV 表目錄 VIII 圖目錄 IX 第一章 前言 1 1-1 研究緣起 1 1-2 研究目的與內容 2 第二章 文獻回顧 4 2-1 含砷廢水之問題 4 2-1-1 砷之特性 4 2-1-2 砷系廢水之來源 7 2-1-3 光電業砷系廢水之處理方 9 2-2 砷系廢水之處理方法 10 2-2-1 沈降法 10 2-2-2 混凝共沈澱 13 2-2-3 吸附與離子交換 14 2-2-4 薄膜過濾 15 2-2-5 小結 15 2-3 電聚浮除法 16 2-3-1 電聚浮除法之原理與去除機制 17 2-3-2 影響電聚浮除法之操作因子 20 2-3-3 電聚浮除法的分類 22 2-3-4 電聚浮除法之優缺點 25 2-3-5 電聚浮除法在去除砷離子之應用 26 2-4 浮除法與界面活性劑之介紹 27 2-4-1 浮除法 27 2-4-2 界面活性劑之分類 28 2-4-3 界面活性劑之基本性質 28 2-4-4 界面活性劑之應用 30 第三章 實驗材料與方法 32 3-1 實驗設備與材料 32 3-1-1電聚浮除設備 32 3-1-2 實驗儀器 36 3-1-3 實驗材料 36 3-2 實驗架構及方法 37 3-2-1 化學固定法 37 3-2-2 低濃度含砷廢水-電聚浮除實驗 39 3-2-3 高濃度含砷廢水-結合鈣鹽之電聚浮除實驗 40 3-2-4 出流水穩定實驗 43 3-2-5 殘餘界面活性劑實驗 43 3-2-6 界達電位分析實驗 44 3-3 分析方法 45 3-3-1 懸浮固體物濃度 45 3-3-2 砷、鋁金屬元素濃度分析 45 3-3-3 殘餘鋁金屬元素濃度分析 45 3-3-4 濁度分析 46 3-3-5 TOC濃度分析 46 3-3-6 界達電位分析 46 3-3-7 pH值 46 第四章 結果與討論 47 4-1 化學沉降法 47 4-1-1 pH值之影響 47 4-1-2 混凝劑之影響 48 4-2 低濃度砷系廢水-電聚浮除實驗 52 4-2-1 極板之影響 52 4-2-2 界面活性劑之影響 53 4-2-3小結 57 4-3 高濃度砷系廢水-結合鈣鹽電聚浮除實驗 58 4-3-1 不同鈣鹽比例與種類之影響 58 4-3-2 界面活性劑之影響 64 4-3-3 電流密度之影響 67 4-3-4 酸度之影響 70 4-3-5 陰離子干擾 75 4-3-6 傳統混凝和電聚浮除法之差異 81 4-4 出流水穩定實驗 82 4-5 殘餘界面活性劑實驗 83 4-5-1 界面活性劑與TOC濃度之關係 83 4-5-2 出流水殘餘界面活性劑之關係 83 4-6 界達電位 84 4-7 表面分析 86 第五章 結論與建議 90 5-1 結論 90 5-2 建議 91 參考文獻 93 附 錄 991345333 bytesapplication/pdfen-US砷系廢水電聚浮除法界面活性劑arsenic-containing wastewaterelectro-coagulation- flotationsurfactants[SDGs]SDG3thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/62728/1/ntu-94-R92541112-1.pdf