評估以HCl與EDTA處理受重金屬污染土壤之效率研究

Evaluating HCl and EDTA for Removal of Heavy Metals from Metal-Contaminated Soils

10.7117/JSET.200612.0039

陳立軒(Li-Hsuan Chen)；蕭伊琳(Yi-Lin Hsiao)；林啓文(Chi-Wen Lin)

土壤 ； 化學萃取 ； 等溫脫附模式 ； 重金屬 ； chemical extraction ； heavy metals ； isothermal desorption model ； soil

科學與工程技術期刊

2卷4期（2006 / 12 / 01）

39 - 44

繁體中文

本研究利用鹽酸(0.05、0.1、0.5、1 M)與EDTA(0.0005、0.001、0.005、0.01 M)以批次方式處理受重金屬污染之土壤，並以Freundlich與Langmuir之等溫脫附模式評估0.1 M鹽酸及0.01 M EDTA對土壤中重金屬鉛、鋅之脫附行為。研究結果顯示，利用鹽酸及EDTA清洗受重金屬污染土壤時，其土壤中之鉛金屬(775.35 mg/kg)可被有效去除達97%(1 M HCl)，0.01M EDTA對於鉛金屬(775.35 mg/kg)的去除效率則可達84%以上，且在酸性環境下重金屬鉛的萃取效果較佳，但隨著pH值增加而效果逐漸下降。在恆溫振盪脫附實驗中發現，對於鉛與鋅金屬之脫附，Freundlich與Langmuir之等溫脫附模式皆可適合模擬土壤重金屬鉛與鋅之脫附行為，其R^2值介於0.92-0.99。

This study examined the release edges of Pb (lead) and Zn (zinc) in contaminated rice soils in Central Taiwan. Concentrations of lead exceeding the trigger levels established by the Environmental Protection Agency of Taiwan were found in a soil sample obtained in Nantou County. Successive extractions with HCl (hydrogen chloride) and EDTA (ethylene diamine tetraacetic acid) ranging from 0.05 to 1 M and 0.0005-0.01M were observed, respectively. The experimental results showed an increase in the release of lead (775.35 mg kg^(-1)), with a declining pH and a removal of as much as 97% by HCl (1 M) extraction and 84% by using EDTA (0.01 M) as a chelating agent. The desorption behavior of Pb and Zn from the soil were all found to be best fitted with the Freundlich and Langmuir model, with R^2 ranging from 0.92 to 0.99.