電鍍污泥中重金屬快速回收之研究

The expeditious recovery of heavy metal from electroplating sludge

郭鼎楠(Ding-Nan GUO)

指導教授 ： 蕭明謙

崑山科技大學/工程學院/環境工程研究所/碩士(2010年)

摘要

離子熔液萃取方式是近年來新穎的有效處理重金屬廢水方式之一，處理後重金屬危害量減少，因此本研究利用離子熔液作為萃取含重金屬廢水的主要萃取劑，將以含有不同重金屬之電鍍污泥加以萃取，並配合微波及超音波的方式有效縮短處理時間。因此本研究包含了兩大部分，分別為快速合成離子液體技術探討與快速萃取重金屬之應用技術。前者包含了微波快速合成技術、兩段式超音波技術，後者則有微波酸萃技術。
本研究首先以甲基咪唑為原料，在開放式微波下，使用溴丁烷進行季胺化反應，最佳反應條件為：甲基咪唑:溴丁烷的莫耳比為1:1，微波功率240 W，在90 ℃下反應2分鐘，離子液體第一段產率可達85%，再以微波進行第二段離子液體合成，產率則可達到75%。另使用超音波混合下最佳條件為：超音波兩段式震盪混合在總反應150分鐘後，甲基咪唑:溴丁烷的莫耳比為10:11，反應溫度85 ℃，振幅60 %為最佳的條件，產率達到75％。
以開放式微波合成疏水性離子熔液在與雙硫腙螯合劑搭配萃取情況下研究結果顯示，恆溫振盪轉數設定在180 rpm，當體積比為1:10，離子熔液添加量1 mL，反應溫度室溫25 ℃，萃取3分鐘，重金屬廢水中重金屬銅萃取率可達90％，而離子熔液所吸附的重金屬離子可利用調整不同pH使離子熔液與產物分離，具有很好的穩定性，且對環境友好。另外，以開放式超音波合成疏水性離子熔液在與EDTA螯合劑搭配萃取情況下研究結果顯示，重金屬廢水中重金屬銅之萃取率可達95％以上。
國內污泥量年年遞增，以化學處理方式頗為費時又耗能，一種嶄新的方法成功地製備奈米氧化銅。首先，利用酸萃取出銅離子，然後，加入乙二醇/水溶液中，在超音波的條件下進行反應，再經由微波高溫烘乾得到氧化銅。同時，改變不同的反應條件，如分散劑劑量、超音波溫度、微波時間，最佳條件－電鍍污泥:硫酸之固液比在1/20時，以微波浸提處理30分鐘、硫酸濃度0.5 M對污泥中重金屬銅溶出率達90%以上。進一步以超音波震盪30分鐘、微波30分鐘，再添加分散劑0.1 g可形成粒徑在40-50μm之氧化銅，並藉由XRD鑑定氧化銅的型態及晶格結構。
傳統照相館之廢定顯影液含有銀離子的成分，環保署僅規定集中回收再次處理，而液體本身含有銀離子，為了不再造成二次污染，本研究將銀離子加以回收再製成奈米銀。一般合成奈米級粒子做法採用水熱合成法，時間長達數個小時之久，其粒徑大小約30~40 nm間，且粒徑大小不易控制，無法形成高均勻性的奈米銀溶液。研究中以超音波合成總時間僅需40分鐘，平均粒徑40-50μm，合成的方式與傳統方法相比可節省近2/3時間。將銀適度奈米化之後，由於表面積大幅提升，衍生出新的功能，使得其應用性大幅增加。
本研究利用離子熔液與螯合劑有效萃取重金屬離子可有效將重金屬抓取90%以上；另以微波及超音波方式快速將廢棄物有效回收再製成新製品應用上相當可觀，同時不論使用微波或是超音波的方式均可有效的縮短反應時間，增加產量，並減少廢棄物耗用，達到資源回收再利用目的。

關鍵字

離子熔液 ； 季胺化反應 ； 微波 ； 超音波 ； 氧化銅 ； 奈米銀 ； 鐵氧磁體

並列摘要

Ionic liquid extraction method was novel in recent years, the effective processing of one form of heavy metal waste, handling hazardous heavy metals from a decline in this study using ionic liquids as extraction of the main waste water containing heavy metals extraction agent, will contain different heavy metal sludge to be extracted and combined with microwave and ultrasound effective way to shorten the processing time.Therefore, this study includes most of order two, namely, rapid synthesis of ionic liquids technology and rapid extraction of heavy metals in the applied technology. The former contains the order microwave synthesis, two-stage ultrasonic technology, the latter of microwave acid extraction technology and ferrite.
In this study first-methylimidazole as the raw material, in an open microwave, the use of butane to quaternary ammonium bromide reaction, the best reaction conditions: molar ratio of 1:1, the microwave power 240W, reaction at 105 ℃ for 2 minutes, ionic liquid yield of 86% for some, and then to carry out the second paragraph of microwave synthesis of ionic liquid, the yield can reach 75%. Under the ultrasonic, taking into account bromobutane may be volatile at room temperature using the heater response manner, using ultrasound to liquid butane with bromine with the heater to full mixing of reactants. Mixed use of ultrasound under the best conditions: ultrasonic two-stage oscillation in the total reaction mixture after 150 minutes, this time for the 10:11 molar ratio, reaction temperature 85 ℃, 60% of the amplitude of the best of conditions, ionic liquid production rate can reach 75% effective. From the results suggest, whether the use of open microwave or ultrasonic, ionic liquids are able to yield more than 70% yield.
Microwave synthesis of an open hydrophobic ionic liquids in combination with the chelating agent dithizone extraction case study results show that temperature oscillation rotation set 180 rpm, when the volume ratio of 1:10, ionic liquid dosage 1ml, room temperature 25 ℃, extraction of 3 minutes, heavy metal extraction rate of copper in waste water up to 90%, while the adsorption of ionic liquids to adjust the metal ion can be used to adjust pH to make ionic liquids easily separated from the product, good stability, and environmentally-friendly. In addition, an ultrasonic synthetic hydrophobic ionic liquids in combination with the chelating agent EDTA extraction case study showed that the extraction rate of heavy metals in waste water up to 95%.
Annual increases of domestic sludge, the chemical treatment are always the solution, rather time-consuming and energy, a new method was successfully synthesis prepared CuO nanoplates. For the preparation of CuO nanoplates, Cu sludge were using acid to extract copper ions, prepared by using of CuO powders immersed in ethylene glycol/water solution under ultrasonic conditions, and then drying by microwave high-temperature CuO nanoparticles obtained. The preparation of CuO nanoplates was studied in several experimental factors, for example reactant amount, temperature, reaction time, and capping agent. The optimal condition was found in which the solid/liquid ratio was used at 1/20 and microwave extraction processing 30min, 0.5M sulfuric acid concentration on the dissolution rate of copper sludge by 90%. Extract further to ultrasonic 30min, microwave for 30 minutes, then add 0.1g dispersant to form particle size of 40-50μm copper oxide. The XRD diffraction were employed to characterize composition, morphology, and structure for CuO.Traditional studio set in the waste developer solution containing silver ions in the composition, the current Taiwan EPA only provides centralized recycling for further treatment, but the liquid itself contains silver ions, in order to not cause secondary pollution, recycling will be made of silver ions. General synthesis of nano-silver particles by hydrothermal synthesis approach, as long as 25 to 40 hours long, the particle size between about 30~40nm, and the particle size and difficult to control, not the formation of silver nanoparticles with high uniformity solution. Synthesis of research with ultrasound only 40 minutes total time average diameter 40-50μm, the composition of some savings compared with traditional methods near 1/1.5 hours. Nano silver, after a moderate, due to the smaller particle size, surface area to increase substantially derived from the new features that make the application was increased significantly.
In this study, rapid synthesis of ionic liquids and the use of ionic liquid with the effective extraction of copper metal ion chelating agent more than 90%. Other means of microwave irradiation and ultrasound irradiation and then quickly and effectively recover the heavy metal made of nanoparticles copper oxide and nanoparticles silver, effectively shorten the reaction time, increase productivity, and reduce carbon emissions up to the purpose.

並列關鍵字

ionic liquid ； quarter amination reaction ； microwave ； ultrasound ； copper oxide ； nanoparticles silver ； ferrites

參考文獻

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