探討電動力法(CEEK)處理實地鉛污染土壤之成效與關鍵因子

Investigation of effectiveness and factors on in-situ electrokinetics (CEEK) for treating pb contaminated soils

賴詠章(Yung-Chang Lai)

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(2013年)

摘要

本研究以近實場規模之電動力法(Circulation-Enhanced Electrokinetics， CEEK)整治南投市某處鉛污染土壤，藉由現地實驗了解近實場規模之電動力法技術的關鍵因子，進而掌握最佳去除效益及操作參數，最後獲得整治復育技術的經濟成本效益。本試驗操作參數包括：系統操作液(0.01 M EDTA-2Na、0.01 M 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10 A、定電壓60 V等。
本研究進行63天污染土壤整治，實驗結果顯示本試驗污染土壤中鉛去除率可達約64%，平均土壤鉛濃度可從7,246 mg/Kg降至約2,612 mg/Kg，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 9.84元，此數據與過去模場試驗的8.82元頗為接近；近實場規模操作下，土壤的pH值及導電度維持在中性及穩定的狀態，呈現電動力整治系統對土壤衝擊低，並且系統電流及電壓均維持在穩定的狀態。同時，系統溫度接近大氣氣溫、操作液及相關設施的穩定性佳，電動力整治方法處理後的土壤肥力略降，需要添加適量的Ca、P當肥料方能回復肥力。

關鍵字

土壤整治 ； 整治復育技術 ； 電動力法

並列摘要

This study is to investigate the critical effects about circulation-enhanced electrokinetics (CEEK) in near-real scale to remediate the Pb contaminated soils in Nantou city. Through this study, the lead removal efficiency and cost effectiveness of CEEK in near-real scale can be obtained. The experimental parameters were controlled as: operation solution (0.01 M EDTA-2Na, 0.01 M Na2CO3); electrode (anode: graphite, cathode: stainless steel); voltage gradient 1 V cm-1.
After 63-day CEEK treatment, the Pb removal efficiency was around 64% and the average Pb concentration was decreased from 7,246 mg/Kg down to 2,612 mg/Kg. The operational cost of electricity of removing 1% lead was around 9.84 NT dollars based on one square meters of polluted soil. This result is similar to our previous study in pilot scale (8.82 NT dollars). Under CEEK operation in near-real scale, the pH and conductivity of the treated soils was maintained at neutral and stable situation, respectively. In addition, the current, voltage, and temperature of CEEK system could be controlled at the stable status as well. The fertilization of the CEEK treated soil was slightly decreased. The fertilizer with Ca and P should be added in the CEEK treated soils.

並列關鍵字

soil contamination ； electrokinetics ； remediation technique

參考文獻

3. Acar, Y. B., Hame, J. T., Alshawabkeh, A. N., and Gale, R. J., “Removal of Cadmium from Saturated Kaolinite by the Application of Electrical Current,” Geotechnique, Vol. 44, No. 2, pp. 239-254 (1994).

5. Alshawabkeh, A. N. and Acar, Y. B.., “Removal of contaiminants from soil by electrokinetics A theoretical treaties,” Journal of Environmental Science and Health, Vol. 27, Part A, pp. 1835-1861 (1992).

7. Al1oway, B.J., Heavy Metal in Soils, John Wiley ＆ Sons NEW York , PP. 122-147 (1995a).

8. Butterfield, R., and Johnson, I. W., “The Influence of Electroosmosis on Metallic Piles in Clay,” Geotechnique, Vol. 30, pp. 17-38 (1980).

10. Chung, H. I. and Kang, B. H., “Lead removal from contaminated marine clay by electrokinetic soil decontamination,” Engineering Geology, Vol. 53, pp. 139-150 (1999).