以模場規模電動力法處理現地鉛污染土壤之研究

Study On In-Situ Treatment of Lead Contaminated Soils by The Pilot-scale Electrokinetics

沈柏丞(Po-Cheng Shen)

指導教授 ： 章日行

朝陽科技大學/理工學院/環境工程與管理系/碩士(2012年)

摘要

本研究主要目的為探討電動力復育技術運用在現地實場上，其去除土壤中重金屬污染物之成效，並尋求影響電動力系統處理成效之因子及經濟效益。試驗以現地鉛污染土壤為目標污染物，先將實場土壤送入實驗室，進行小型模場之試驗，了解其處理成效與電化學反應現象，如電滲透流、離子遷移、電解作用等，進而將系統放大至現地規模，分別處理位在台中縣及南投市污染場址的土壤。操作參數包括：系統操作液(0.01M EDTA-2Na、0.01M Na2CO3)、電極板 (陽極：石墨板、陰極：不鏽鋼板)、電壓梯度1 V cm-1、定電流10A、定電壓80V等。在整治過程中，針對系統中(1)操作液之pH、導電度值、鉛濃度、(2)土壤pH、導電度值、鉛濃度、(3)電流、電壓、溫度及肥力分析試驗 (Ca、Mg、K、Na、F、Mn、Cu、Zn、P、OM、CEC)等進行分析監測，藉此了解此技術對現地受鉛汙染土壤處理之成效並估算其耗電量等成本。
實驗結果顯示，在烏日場址經過56天處理時間，土壤平均鉛濃度可從7190 mg Kg-1降至約2050 mg Kg-1，去除效率約可達72%。而在南投場址目前僅進行14天處理時間，土壤平均鉛濃度由7246 mg Kg-1降至約6647mg Kg-1，去除效率約可達10%，系統仍持續操作中。此外，由實驗可發現，電動力系統以循環方式操作並以0.01M Na2CO3及0.01M EDTA作為操作液時，其土壤並沒有酸化現象產生。
在操作成本方面，以烏日場址為例，系統對於1.0平方公尺的鉛污染土壤每去除1%所需的操作電費約為 8.82元。若以移除100mg Kg-1 Pb所需之操作費用約為12.6元。

關鍵字

酸化現象 ； 電動力法 ； 整治復育技術 ； 離子遷移

並列摘要

The purpose of this study is to discuss the removal efficiency of heavy metal pollutants in the soil and economic cost by the in-situ pilot-scale electrokinetics. First, it will proceed the removal efficiency experiment of lead form the in-situ soil by the small pilot-scale electrokinetics in laboratory. It is to understand the electrochemical phenomenons of the electro-osmosis flow, ion migration and electrolysis effectiveness etc. Second, it will proceed the in-situ experiment in taichung and nantou that the operating parameters include: system electrolyte (0.01M EDTA-2Na, 0.01M Na2CO3), electrode material (Anode: graphite plate, Cathode: stainless steel plate), the voltage gradient, constant current and constant voltage are 1 V cm-1, 10A and 80V, respectively. In the remediation process, it will be analysis and monitoring that (1) the pH and conductivity values and lead concentration of the system electrolyte, (2) the pH and conductivity values and lead concentration of the soil, (3) current, voltage, temperature and fertility test (Ca、Mg、K、Na、F、Mn、Cu、Zn、P、OM、CEC). All of them to understand the removal efficiency of lead in the in-situ soil by electrokinetics and to count the power consumption costs.
Form the experimental results show, passed through 56 days treatment, the mean concentration of lead in the soil was from 7190 mg Kg-1 to 2050 mg Kg-1 in wuri site. The removal efficiency is around 72%. In nantou site, the mean concentration of lead in the soil was from 7246 mg Kg-1 to 6647 mg Kg-1 that removal efficiency about 10% by 14 days treatment. In addition, the soil not happened the acidification in the electrokinetics with the 0.01M Na2CO3 and 0.01M EDTA operated.
In the aspect of tlhe operating costs that example of the wuri site. The 1% removal efficiency of lead per 1.0 m2 is around NT. 8.82 dollars. It needs NT. 12.6 dollars to remove 100 mg Kg-1 Pb.

並列關鍵字

Acidification ； Electrokinetics ； Ion migration ； Remediation technologies

參考文獻

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行政院環境保護署，「土壤污染監測基準」，(2001)。