萃取新技術:微米油膜氣泡萃取系統 (CASE)

Compressed air-assisted solvent extraction (CASE) for metal removal

蕭世典(Shin-Tien Hsiao)

指導教授 ： 李奇旺

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2007年)

https://doi.org/10.6846/TKU.2007.00905

摘要

過去眾多的萃取程序都有其缺點，如產生大量金屬污泥、處理時間冗長與使用萃取劑藥量過多…等。尤其是處理低濃度的廢水更為棘手，因為使用混凝沉澱會產生大量且含水量高的汙泥，若使用其他種處理程序也會受限於廢水中金屬濃度過低導致效率下降等的問題。
本研究氣泡油膜萃取系統(CASE)就是利用將萃取溶劑加壓後釋壓的程序快速且大量的釋放在廢水中，如此ㄧ來可在短時間內，使用少量的萃取溶劑處理大量重金屬廢水的系統，尤其是針對低濃度的金屬污水。這是一個令人興奮且創新的技術，最主要的目的在於希望能透過本系統，在可預見的將來處理重金屬廢水不會再產生大量的重金屬污泥，也無需投入大量萃取劑，最重要的是可以明顯縮短處理重金屬污水上的時間與提升系統濃縮比。
實驗結果發現氣泡油膜萃取系統(CASE)的確可以在短時間內將低濃度的廢水處理完成，如處理500ml (50ppm)的Cd金屬廢水時，利用CASE系統需使用了溶劑比為5：1的溶劑0.96克，再將pH值調整到6，處理效率變可達到約為95%以上的效果，處理時間不需1分鐘。系統濃縮比可達到高達1042倍，對於過去萃取程序來談這是一個很大的突破。

關鍵字

Cd(II) ； 萃取 ； 壓力 ； 氣泡油膜 ； kerosene ； D2EHPA

並列摘要

Compressed air-assisted solvent extraction (CASE) was developed to generate micro-sized solvent-coated air bubbles (5~30μm) which were employed for metal extraction. Through pressurization of solvent (mixtures of extractant and diluent) with compressed air followed by releasing air-oversaturated solvent into metal-containing wastewater, micro- sized solvent-coated air bubbles were generated instantaneously creating enormous surface area between solvent and aqueous phases.
Applied the proposed process for Cd(II) removal from wastewater (Cd=100mg l-1) and can be achieved with aqueous/solvent weight ratio ratio of 1042 and extraction time of less than 60 sec with solvent having D2EHPA/kerosene weight ratio of 5:1.
CASE is a efficient systematic for dispose of wastewater.Making extraction process extremely fast and achieving very high aqueous/solvent weight ratio

並列關鍵字

Pressurization ； extraction ； Cd(II) ； D2EHPA ； kerosene

參考文獻

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