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Title: | 以微波加熱氧化法利用工業廢水製備合成硫酸鐵之研究 Production of Polyferric Sulphate from Industrial Wastewater by Microwave Heating Oxidation |
Authors: | Zhijie Zhang 張智杰 |
Advisor: | 駱尚廉(Shang-Lien Lo) |
Keyword: | 硫酸?(PFS),微波加熱氧化法,混凝,複合型無機混凝劑,製備, Polyferric Sulfate(PFS),Microwave Heating Oxidation,Coagulation,Composite inorganic coagulants,Preparation, |
Publication Year : | 2017 |
Degree: | 碩士 |
Abstract: | 摘要
混凝是一種有效的環保技術,被廣泛地應用於諸如工業和農業淨水廠等廢水處理設施上。其通過破壞膠體懸浮物的穩定性來去除廢水中的懸浮顆粒、濁度和化學需氧量。近年來,越來越多的研發者對復合型無機混凝劑的合成產生興趣。其中一個典型的案例是合成鐵的製備。硫酸鐵是一種較為新型的混凝劑,擁有高電荷陽離子。本研究採用新的製備方法微波加熱氧化法來製備硫酸鐵,包括化學氧化劑的種類、氧化劑投加量、反應溫度(微波功率)、反應時間因素探討。同時,通過檢測還原性二價鐵含量、總鐵含量、pH值、鹽基度這些主要參數來評估最佳化的製備操作情形。 (1) 通過對比不同的氧化劑來探究硫酸鐵的製備最佳化操作。在過氧化氫方面,實驗探索之最佳操作條件如下:在100毫升的工業廢水中加入39.35毫升的過氧化氫溶液,在微波中功率下加熱50分鐘。而在氯酸鈉方面,實驗探索之最佳操作條件如下:在100毫升的工業廢水中加入1.86克的氯酸鈉溶液,在微波低功率下加熱40分鐘。另外,在硝酸方面,實驗探索之最佳操作條件如下:在100毫升的工業廢水中加入6.03毫升的硝酸溶液,在微波中功率下加熱40分鐘。 (2) 在理論上添加氫氧化鈉可以提升硫酸鐵的鹽基度,因此,需要探究往硫酸鐵添加氫氧化鈉之最佳化操作條件。實驗係對比添加不同劑量的氫氧化鈉所造成的情形。50毫升的硫酸鐵溶液在攪拌時分別添加6、9和12毫升的氫氧化鈉溶液,發現產品的鹽基度由原來的3-4%提升到8-11%。由此,實驗證明添加適量的氫氧化鈉溶液可以提升硫酸鐵產品的鹽基度。 (3) 通過對洗衣廢水之杯瓶實驗來評估硫酸鐵產品的去除效率。本研究在試驗開始前記錄下200毫升洗衣廢水的初始濁度和化學需氧量。而後調節每個燒杯的pH值並添加遞增劑量的硫酸鐵溶液,接著開啓混凝機。杯瓶實驗過程如下:快混100rpm 3min,慢混30rpm 15min,靜置12min。實驗結果顯示,最適pH值為7,最適添加劑量為0.2-0.4毫升。濁度和化學需氧量的去除率皆超過90%,表明製備出的硫酸鐡有良好的混凝效果。 Abstract The coagulation process is an effective environmental protection technology, which is widely used in the wastewater treatment facilities, such as purification treatment of industrial and agricultural waste water, for the destabilization of colloids suspensions and for the removal of suspended solids along with the removal of turbidity and Chemical Oxygen Demand (COD). In recent years, more and more researchers are interested in the synthesis of composite inorganic coagulants. A characteristic example is Polyferric Sulfate(PFS), which is a relatively new poly inorganic coagulation with high cationic charge. In this study, the Microwave Heating Oxidation process, a new preparation method for Polyferric Sulfate was investigated, including types of chemical oxidant, doses of chemical oxidant, reaction temperature (or microwave power), reaction time. And the optimum preparation operation was evaluated by the role of major parameters, including ferrous concentration, total iron concentration, pH value, Alkalinity. Firstly, the optimum condition of coagulant PFS preparation was investigated, by comparing different oxidants (Hydrogen Peroxide, Sodium Chlorate, Nitric Acid). For Hydrogen Peroxide, the optimum condition decided by experiments are as follows: 39.33mL of Hydrogen Peroxide were added to the raw materal, 100mL of ferrous industrial wastewater, reacting in microwave oven, under 127W, for 50min. Besides, for Sodium Chlorate, the optimum condition decided by experiments are as follows: 1.86g of Sodium Chlorate were added to the raw materal, 100mL of ferrous industrial wastewater, reacting in microwave oven, under 36W, for 40min. Additionally, for Nitric Acid, the optimum condition decided by experiments are as follows: 6.03mL of Nitric Acid were added to the raw materal, 100mL of ferrous industrial wastewater, reacting in microwave oven, under 127W, for 40min. Thus, the product liquid polyferric could be obtained. Secondly, using Sodium Hydroxide could raise the basicity of Polyferric Sulfate theoretically, hence, the optimum operation of adding Sodium Hydroxide into coagulant PFS was investigated, by comparing different dosages of Sodium Hydroxide. The condition decided by experiments are as follows: 6, 9 and 12mL of Sodium Hydroxide were added to the coagulant products, 50mL of Polyferric Sulfate, under stirring. And the basicity increased from 3-4% to nearly 8-11% respectively. The experiment proved that adding appropriate doses of Sodium Hydroxide could raise the basicity of PFS products significantly. Thirdly, operation cost was an important factor for evaluating feasibility of the three kinds of PFS products. The highest cost was 9.73 Taiwanese dollars per liter for Hydrogen Peroxide and the mediate cost was 2.73 Taiwanese dollars per liter for Nitric Acid. The lowest cost was 1.09 Taiwanese dollars per liter for Sodium Chlorate. Finally, the coagulation efficiency of Polyferric Sulfate products in treating laundry wastewater was evaluated by jar test. In this study, we recorded the turbidity and Chemical Oxygen Demand of 200mL laundry wastewater before beginning, and used the prepared solution of PFS, dosed each beaker with adjusted pH values and increased amounts of solution. After dosing each beaker, turned on the stirrers. The jar test would be performanced as follows: Operated the stirrers at 100 rpm for 3 minutes, then reduced the speed to 30 rpm for 15 minutes and allowed setting for 12 minutes. According to the results, the best pH values were about 7 and the proper dosages were 0.2-0.4mL. Turbidity and COD removal rate were more than 90%, which showed that prepared Polyferric Sulfate had very good coagulation performance. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/76586 |
DOI: | 10.6342/NTU201701020 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 環境工程學研究所 |
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ntu-106-R04541140-1.pdf Restricted Access | 2.46 MB | Adobe PDF |
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