沸石表面改質十八烷基三氯矽烷應用於吸附不同水溶解度之有機物可行性研究

Sorption of organic compounds with different water solubility on modified-NaY zeolite using octadecyltrichlorosilane

彭俊倫(JYUN-LUN PENG)

指導教授 ： 趙煥平

中原大學/工學院/土木工程研究所/碩士(2010年)

https://doi.org/10.6840/CYCU.2010.00553

摘要

摘要
本研究主要在探討以十八烷基三氯矽烷(OTS)與不同蒸餾水混合改質Na Y沸石，並以此改質沸石針對不同水溶解度有機物吸附，藉由吸附等溫線所得之結果，探討所選擇有機物與改質沸石間的作用機制與可能之吸附容量。
OTS與1.0ml與2.0ml水混合改質Na Y沸石後將改變原Na Y沸石的有機質含量與表面疏水性，因此對於改質後沸石將以SEM、FTIR、元素分析儀及氮氣吸/脫附曲線測量得沸石之表面性質，包括BET比表面積、孔洞體積、孔洞大小分佈等。吸附目標實驗所使用的有機物可分為三類包括(一)低水溶解度芳香族有機物：苯、甲苯、乙苯、二甲苯、丙基苯，(二) 高水溶解度脂肪族有機物：正戊醇、三氯甲烷，(三)高水溶解度芳香族有機物：酚、鄰-甲基酚；實驗結果經由吸附溫線形狀使用Freundlich等溫吸附模式、Langmuir等溫吸附模式，探討目標物對改質沸石之作用機制。
所得結果顯示OTS改質後的Na Y沸石對低水溶解度有機物的吸附能力明顯增加，且對低水溶解度化合物吸附等溫線接近直線代表其主要作用機制可能為兩相分佈(partitioning)，脂肪族化合物中三氯甲烷的吸附等溫線類似於低水溶解度之有機物，但是在水溶解度較高的正戊醇對改質或未改質沸石之吸附等溫線均呈現凹面向下，代表沸石對戊醇具有高吸附能力且主要作用機制為吸附(adsorption)，改質與未改質沸石對酚、鄰-甲基酚皆具有高吸附能力，但其機制複雜需進一步研究才能夠確認。

關鍵字

OTS ； Y沸石 ； 土壤有機質 ； BTEX ； 吸附 ； 分佈作用

並列摘要

Abstract
The objective of this study was to examine octadecyltrichlorosilane(OTS)-modified Na Y zeolite adsorbs organic compounds with different water solubility . The surface characteristics of modified-zeolites were analyzed based on the SEM, FTIR, BET area and element analyzer. The isotherms are applied to explain the mechanism between modified-zeolites and the test organic compounds. The potential sorption capacity was also evaluated in this study.
Mixing OTS with 1.0 ml and 2.0 ml water adsorbed on the NaY zeolite can produce the modified Na Y zeolite possessing different surface hydrophobicity. We measured the surface properties of zeolite, including the BET surface area, carbon content, functional group, pore volume, pore size and pore distribution via the above instruments. The test organic compounds are divided into three groups. The first group is less-soluble aromatic organic compounds: benzene, toluene, ethylbenzene, o-xylene, isopropyl benzene; the second group is relatively high-soluble aliphatic organic compounds: n-pentanol and trichloromethane; the third group is relatively high-soluble aromatic organic compounds: phenol, o-cresol. The obtained data regarding sorption are fitted using Freundlich model and Langmuir model.
The results showed that the adsorption capacity of modified-zeolites to trichloromethane and organic compounds with the low water solubilities increased significantly. The isotherms are close to being linear, suggesting that the primary mechanism might be partitioning. The isotherm for pentanol is a concave downward curve, which indicates a high adsorption capacity. It is also found that modified- zeolites posses high adsorption capacities for phenol and o-cresol. However, mechanisms between adsorbents and adsorbates need to be investigated in the further.

並列關鍵字

Organic Compound ； Sorption ； Zeolite ； octadecyltrichlorosilane

參考文獻

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