沸石表面改質十六烷基三甲基溴化胺應用於同時吸附水中重金屬和有機物之研究

Adsorption of heavy metals and organic compounds on zeolite modified by hexadecytrimethylammouium bromide

羅時軒(Shih-Hsuan Lo)

指導教授 ： 趙煥平

中原大學/工學院/生物環境工程研究所/碩士(2013年)

https://doi.org/10.6840/cycu201300912

摘要

因應工業的快速發展，許多含有重金屬和有機物的廢液被大量產生，但在處理過程中常需要複雜的操作程序，因此本研究以十六烷基三甲基溴化胺(HDTMA)與氫氧化鈉(NaOH)改質沸石，使沸石成為可吸附多種類污染物之吸附劑，以增加吸附劑應用的空間。經HDTMA改質前後之沸石以及含有重金屬之沸石將利用界達電位、CEC、ECEC、SEM、EDS等鑑定吸附劑之性質。實驗所使用的吸附質分為兩類，第一類為重金屬，包括銅、鎳、鉛等三種陽離子，與一種陰離子鉻；第二類為有機物，包括苯、甲苯、乙苯、丙基苯以及酚，其中酚有較高之水溶解度，其餘皆為低水溶解度之有機物。吸附實驗所得結果利用Freundlich和Langmuir等溫吸附模式探討吸附質對改質沸石之作用機制並估算最大吸附容量。
實驗結果顯示改質後的吸附劑表面電性可從原本的負電轉為正電，性質也從原本的親水轉成疏水性質。改質沸石時，因HDTMA無法進入沸石之小孔洞中使孔洞內部仍具有陽離子交換位置，因此改質後的吸附劑可同時吸附重金屬陽離子與陰離子。又考慮改質過後的沸石將呈現表面疏水但內部孔洞親水之特性，因此低水溶解度有機物可以利用分佈的方式進入沸石外部表面的HDTMA，而親水性有機物則可以吸附於沸石內部孔洞表面。綜合以上，利用NaOH與HDTMA改質之沸石先吸附陽離子重金屬後吸附陰離子重金屬，再利用此含有重金屬之沸石吸附有機物，此改質與吸附順序可以得到這些吸附質吸附效果的最佳化。

關鍵字

Y沸石 ； 吸附 ； 重金屬離子 ； 有機物 ； HDTMA

並列摘要

The objective of this study is to develop a new adsorbent that can adsorb cationic and anionic heavy metals, and organic compounds with various water solubilities. The zeolite Y modified by hexadecytrimethylammouium bromide (HDTMA) and sodium hydroxide (NaOH) was used as the adsorbents. Copper(II), lead (II), nickel(II), dichromate, benzene, toluene, ethylbenzene, propylbenzene, and phenol were selected as the target adsorbates. The surface characteristics of modified-zeolites were analyzed by the CEC, ECEC, SEM, EDS and zeta potential. The Freundlich and Langmuir isotherms are applied to explain the mechanism between adsorbents and the target adsorbates. The potential sorption capacity was also evaluated in this study.
The results showed HDTMA can’t enter the micropores. Thus, the HDTMA-modified zeolites (HMZ) possess positive charge on external surface and negative charge on internal surface of pore that can adsorb cationic and anionic heavy metals. The ion exchange is the primary mechanism between adsorbates and adsorbents. The surface precipitation and complexation is also potential mechanisms. Moreover, the HMZ has hydrophobic and hydrophilic surface, which can adsorb organic compounds with various water solubilities. The less-soluble organic compounds could partion onto the HDTMA on the HMZ surface. The high-soluble organic compound could adsorb on the internal surface of pore. The HMZ can be regarded an excellent adsorbent to remove various contaminants.

並列關鍵字

zeolite Y ； adsoption ； heavy metals ； organic compounds ； HDTMA

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