流體化床結晶技術處理含銅廢水之實廠研究

In-plant treatment process of fluidized bed crystallizers in the removal of copper-containing wastewater

黃孝儒(Shiao-Ju Huang)

指導教授 ： 楊萬發

國立臺灣大學/工學院/環境工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.01500

摘要

流體化床結晶技術應用於工業及生活污水中離子性污染物的去除已行之有年，然而在國內的應用上，尚有其可待發展之處。本研究利用流體化床結晶槽進行銅離子去除之實驗，擬針對實際工業廢水之反應條件，對流體化床之去除效果進行分析及討論。實驗的重點在探討加藥方式、水利負荷、出流水pH值控制及迴流比等操作條件對去除反應之影響，並比對其處理效率。
將反應維持在結晶之介穩區內為流體化床操作的首要重點，而改變操作參數的目的，皆與調整此一反應狀態有直接的關聯。最佳操作條件的實驗結果發現，控制管柱末端的pH值可維持反應槽有穩定的銅出流，而pH控制在9時可得最佳的處理效率﹔水利負荷的方面，42〜46 m/h時有相對較好的成效﹔迴流比以10倍為較佳。實廠的操作上，最佳操作參數的組合可將銅離子的去除率提升至99%以上。另外，藥劑濃度及擔體粒徑等亦對處理效果產生影響。在這些分析的過程中，沉澱比的高低成為評估反應狀況的重要指標。詳細的實驗結果於本文第四章進行探討。
對於實廠處理的整體效能評估，本研究有以下所得：1. 連續操作的處理效率受到變動的進流水質影響，而反應系統本身的循環狀態亦有所關連；2. 在實際的應用上，廢水經流體化床出流後可搭配過濾設備，以平衡不穩定狀態所造成的效率降低﹔3. 除了目標物銅離子外，流體化床系統對同時存在的其他種類重金屬，亦可進行相當程度的處理。除此之外，異常的處理狀況及串聯式管柱的效能亦被列入討論。
最後，實驗在分析反應擔體的組成成分、含水量，並進行SEM之表面欇像後，對流體化床設備進行粗略的經濟效益評估。則單就所節省污泥處置的費用上，每處理一公噸廢水約可幫業主節省達9.68元新台幣的開銷。

關鍵字

流體化床結晶槽 ； 實廠廢水 ； 介穩區 ； 沉澱比 ； 銅去除率 ； 過濾處理

並列摘要

Fluidized bed reactors (FBRs) have long been utilized in the removal of pollutant ions; however, these technologies in Taiwan were relatively immature. The objective of this work was to study the feasibility of real-plant process of fluidized bed crystallizers in the treatment of copper-containing industrial wastewater. In order to achieve a high efficiency of copper removal, some important factors including dose manner, hydraulic loading, effluent pH control, and recycle ratio were investigated.
In this part of the experiments, the main point was to maintain the crystallization condition in the metastable region, and controlling several factors helped attain this purpose. Results showed that the optimum removal could be reached when the effluent pH was controlled at the level of 9.0, and the treated water had a stable Cu concentration as well. Hydraulic loading also had significant influence on the removal of Cu. When the hydraulic loading was adjusted to 42~46 m/h, the FBR had the relatively best efficiency of Cu removal. Moreover, maintaining the recycle ratio at 10/1 was the most suitable for the FBR system. Under these conditions, the Cu removal could be achieved above 99%.
When the experiments were focused on in-plant treatment, there were some results presented in this work. First, fines producing in the FBR tanks – causing higher precipitation ratio – were also investigated because they were important indicators of poor crystallization. Second, in the continuous treatment process, the efficiency of FBRs was affected gravely by the changeable concentration of inflow wastewater. Finally, filtration units locating after the FBR treatment process was necessary to the removal of fines and to the stability of effluent water.

並列關鍵字

fluidized bed reactor ； in-plant study ； metabolism ； fines ； precipitation ratio ； Copper removal ； filtration

參考文獻

詹豐隆(2004)，含鎳廢水流體化床結晶處理技術之應用，國立台灣大學環境工程學研究所，碩士論文

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Egirani, D. E., Baker, A.R., Andrews, J. E. (2005) Copper and zinc removal from aqueous solution by mixed mineral systems I. Reactivity and removal kinetics, J. Colloid Interf. Sci. 291, pp.326-333

Guillard, D., Lewis, Alison E. (2001), Nickel carbonate precipitation in a fluidized-bed reactor, Ind. Eng. Chem. Res. Vol. 40, No. 23, pp. 5564-5569