Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/5671
標題: 土壤中水分境況與溫度效應對於重金屬吸附與脫附行為之探討
The Effects of Moisture Conditions and Temperatures in Adsorption and Desorption on Heavy Metals in Soils
作者: 胡伯瑜
Hu, Po-Yu
關鍵字: Adsorption;吸附;Desorption;Field conditions;Thermodynamics;Wet-dry cycles;Heterogeneous;Soil texture;Organic matter;脫附;天然環境;熱力學;乾溼交替;非均質相;土壤質地;有機質
出版社: 環境工程學系
摘要: 
土壤中重金屬對於生物造成之毒害主要經由脫附作用(desorption)進入水體所形成。本研究以五種台灣地區具代表性之土壤以六種重金屬:六價鉻(Cr〔VI〕)、汞、鉛、鎘、鎳、銅,分別以不同之水分境況與溫度效應模擬天然環境,對於土壤中重金屬吸附與脫附行為進行探討。其中溫度效應試驗結果以熱力學(Thermodynamics)推估模式加以驗證。
實驗結果顯示無論任何條件,於72小時脫附過程內重金屬在土壤中脫附量皆遠低於吸附量;其中水分境況實驗結果顯示無論各種質地之土壤,皆表現出在水分乾溼交替循環(wet-dry cycles)次數愈多,脫附量愈少的趨勢。溫度效應則明顯說明,重金屬脫附量隨升高溫度而增加的趨勢。
實驗中六種重金屬對於台灣地區五種代表性土壤顯示脫附反應發生之潛勢與熱力學推導之趨勢大致符合。此證明熱力學亦能大致提供非均質相(heterogeneous)土壤系統內反應發生之預測。
五種代表性之土壤在相同模擬天然條件下,對於重金屬脫附能力主要受土壤質地(soil texture)與有機質含量所影響。研究結果對於台灣地區接近與類似實驗土壤性質之區域重金屬整治與使用可提供依有利之參考依據。

The toxicity potential of metals in the soils is dependent upon the ability of the metal desorption into the aqueous phase. The adsorption, desorption behavior of Cr(Ⅵ), Hg, Pb, Cd, Ni, and Cu on five characterized Taiwan soils were studied. To simulate field conditions, the soils were subjected to various moisture and temperature conditions. Both adsorption and desorption measurements on the soils were conducted. The comparison between thermodynamic prediction model and empirical experimental results of temperature effect was applied.
All the experimental data showed, that the desorption amount of heavy metals in soils is far less than the amount of adsorption in 72 hours with various treatment conditions. The amount and rate of desorption were found to decrease with increasing number of cycles and decreasing temperature. In this study, the desorption results of six metals onto five soils collected in Taiwan via different temperatures proved that thermodynamic information almost can offer the reacting prediction in heterogeneous systems such as soil environment.
The wet-dry cycle and temperature effects on the desorption of metals from soils are related to the soil composition, with desorption being easiest from sandy soil with low organic content. The desorption process is much slower than the adsorption process. It is expected that researchful results will be beneficial to the remediation and suitable use of the soils with similar characteristics.
URI: http://hdl.handle.net/11455/5671
Appears in Collections:環境工程學系所

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