擦洗程序應用於去除受污染土壤中重金屬之研究

A Study on the Attrition Scrubbing Process Applying to Removal of Heavy Metals from Contaminated Soils

許智為(Zhi-Wei Xu)

指導教授 ： 柯明賢

國立臺北科技大學/工程學院/資源工程研究所/碩士(2013年)

https://doi.org/10.6841/NTUT.2013.00053

摘要

由於受重金屬汙染土壤中之污染物較易吸附或鍵結於土壤顆粒的表面，因此，本研究探討將擦洗法應用於受重金屬污染土壤整治之可行性。本研究以礦漿濃度、擦洗時間、轉速等操作條件進行受重金屬污染土壤之擦洗實驗，而本研究以XRF進行受重金屬污染土壤中重金屬濃度分析，分析不同粒徑土壤中重金屬含量之分布，以探討不同擦洗條件對受重金屬污染土壤整治效果之影響，並評估擦洗法應用於受重金屬污染土壤整治之可行性。本研究係以兩處不同污染特性之受重金屬污染土壤(NS、SS)作為研究對象，經基本特性分析之結果，可發現NS土壤中的重金屬As、Cu、Pb濃度均超過土壤管制標準，SS土壤中的重金屬As、Cr濃度也超過土壤管制標準。另外以SEM顯微結構觀察可以發現兩批土樣的粗顆粒土壤表面含有大量的極細顆粒汙染物。另外。而經擦洗實驗結果可以發現，針對NS、SS受重金屬污染土壤以礦漿濃度70%、擦洗時間15分鐘、轉速為1400 rpm為最適之擦洗操作條件，且由擦洗前後重金屬結合型態分析結果可以發現，擦洗程序對於土壤中重金屬Cr、Cu、Pb之鐵錳氧化態與碳酸鹽態的去除有明顯增加的趨勢，對於土壤中之As結合型態卻無顯著的影響，因此，綜合以上研究結果可以得知，利用擦洗程序做為受重金屬污染土壤之前處理具有可行性，可有效提升細顆粒土壤中重金屬之富集效果，而有助於後續土壤分級處理之分離效率。

關鍵字

擦洗 ； 重金屬 ； 受污染土壤 ； 分離 ； 富集

並列摘要

The fine fraction of contaminated soil particles (clay and silt) tends to concentrate with heavy metals, so it is important to find effective ways of separation between coarse and fine particles on pollution control of heavy- metals contaminated soils. In this study, the attrition scrubbing process was performed to investigate the influence of scrubbing conditions, including slurry concentration, scrubbing time, stirring speed, on enrichment of heavy metals in contaminated soils. In addition, through sequential extraction experiments, the chemical characteristics including existence pattern of heavy metals of contaminated soil before and after scrubbing were compared.
From the results of chemical characterization, it showed that the NS soil was contaminated with Cu, Pb, As, and the SS soil was contaminated with Cr, As. The concentrations of the above heavy metals in these two soils exceeded the regulatory threshold established by the Environmental Protection Agency of Taiwan. By SEM observation of soil surface, it found that a large quantity of finer particles with pollutants is attached to the coarse surface of soil particles. The results of attrition scrubbing test showed that the optimum conditions for separating Cu, Pb, As and Cr from the contaminated soil or concentrating them into a particular soil fraction were at 70 % of solid slurry, scrubbing time of 15 minutes and impeller speed of 1400 rpm. It is obvious that the finer soil particle is, and the higher heavy metal concentration is. Based on the above results, it is feasible that the attrition scrubbing is used for pretreating heavy metal-contaminated soil to concentrate heavy metal content on finer particles.

並列關鍵字

attrition scrubbing ； heavy metals ； contaminated soils ； separation ； enrichment

參考文獻

[32] 黃亮順，擦洗技術應用於廢污中重金屬分離之研究，碩士論文，國立成功大學環境工程學系，台南，2010。

[38] 李方利，擦洗技術應用於受砷污染土壤整治之研究，碩士論文，國立台北科技大學，台北，2012。

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