Effects of Organic Matter Content on Pore Structure and Water and Organic Vapors Adsorption of Soils

有機質含量對於土壤孔洞結構及揮發性有機物及水氣吸附之影響

巫健次(Chien-Tzu Wu) ； 黃富昌(Fu-Chang Huang)

《界面科學會誌》 29卷3&4期 (2007/12) Pp. 137-147

https://doi.org/10.30020/JCCIS.200712.0002

摘要

本研究經由量測氮氣、水氣、苯、正己烷及環己烷氣體在含不同有機質含量之三種固體（包含膨潤石及兩種天然土壤）上之平衡吸附曲線來探討土壤有機質含量對於土壤孔洞結構及其對揮發性有機物及水氣吸附之影響。首先，經由對氮氣吸附曲線作傳統及碎形分析以獲得吸附劑之表面積及孔洞結構參數。接著，量測室溫下水氣、苯、正己烷及環己烷氣體之吸附平衡曲線。研究結果發現吸附劑之平均孔洞大小及孔洞連結度（表面積，總孔隙體積，表面粗糙度）正比於（反比於）吸附劑之有機質含量。另一方面，膨潤石及peat所具有之高水氣吸附量和土壤無機質及有機質所具有之極性特徵有密切關係。另外，peat（膨潤石）對苯（正己烷及環己烷）具有最高的吸附量。本文並對表面積及孔洞結構對土壤吸附有機氣體之影響作了一些討論。

關鍵字

土壤有機質含量 ； 吸附 ； 水氣 ； 揮發性有機物

並列摘要

Vapor adsorption of water, benzene, hexane, and cyclohexane on three natural solids (a bentonite and two soils) that covered a wide range of soil organic matter (SOM) content were measured to examine the effects of SOM on the adsorption of water and volatile organic compounds (VOCs). The surface area and pore structure of the examined solids were first characterized based on the classical and fractal analyses of the nitrogen adsorption isotherms. The adsorption isotherms of water and VOCs vapor at room temperature were then determined. It was found that the average pore diameter and pore connectivity (surface area, total pore volume, and surface roughness) of solid is proportional (inversely proportional) to the fraction of organic matter in the solids. On the other hand, the high adsorption capacity of polar liquids (water) on bentonite and peat is consistent with the polar nature of the soil mineral and organic matter. Moreover, for benzene (hexane and cyclohexane) adsorption, peat (bentonite) possessed the highest adsorption capacity among the examined solids. The effects of both surface area and pore structure on the organic vapor adsorption characteristics of natural solids are discussed.

並列關鍵字

SOM ； adsorption ； water ； volatile organic compounds