土壤中五氯酚污染物整治技術研究

Study on Remediation Technologies for Pentachlorophenol Pollutant in Soil

蘇益民(I-Min Su)

指導教授 ： 劉敏信

朝陽科技大學/理工學院/環境工程與管理系/碩士(2009年)

摘要

氯酚化合物是自然中難分解之物質，本研究希望利用Fenton氧化法（過氧化氫+亞鐵離子），TiO2光催化降解、生物界面活性劑環糊精淋洗及超臨界二氧化碳萃取，去除破壞土壤中之五氯酚，以達到五氯酚在環境中減量之目的。本研究所採用土樣為台灣中部地區常見之紅壤及沖積土，首先分別進行特性分析與探討，並於實驗室將其配置受五氯酚污染之土壤。Fenton氧化法實驗結果H2O2濃度206 mM、Fe2+濃度57.6 mM為紅壤之最佳操作條件，去除率可達75%，沖積土則需提升H2O2濃度至825 mM才有70%以上之降解效果。環糊精淋洗紅壤藥劑濃度1 mM水平震盪可達60%以上之去除率，沖積土可達80%以上。超臨界二氧化碳萃取實驗，分別以不同溫度、壓力、修飾劑比例進行探討。以壓力100 bar，溫度70℃的狀態下，紅壤及沖積土皆可達萃取效率60%以上，而添加5%(v/v)甲醇修飾劑可增加約10%之萃取率，但添加過多之甲醇修飾劑10%萃取效率反而下降。最後將超臨界流體萃取出之五氯酚濃縮液進行Fenton 氧化試驗，過氧化氫206 mM與亞鐵離子14.4 mM，當濃縮液：H2O2：Fe2+為2：5：5 體積比例之Fenton藥劑使用量以上時，五氯酚皆可達降解效率95%以上。比直接使用Fenton藥劑添加於土壤的需要量大幅減少，而且效果較佳。

關鍵詞︰超臨界流體萃取、土壤、五氯酚、Fenton氧化法、環糊精

關鍵字

Fenton氧化法 ； 五氯酚 ； 土壤 ； 環糊精 ； 超臨界流體萃取

並列摘要

Chlorophenol compounds are difficult to break down naturally in the environment. This study was to use Fenton oxidation, TiO2 photocatalytic degradation, biological surfactants cyclodextrins washing, supercritical carbon dioxide extraction to remove or destroy pentachlorophenol in soils, it has reached in the environment PCP reduction purposes. Soil samples used in this study were obtained from the central region of Taiwan, and were the common red and alluvial soils. The characteristics of soils was analyzed and discussed, herein the contaminated soil was prepared by spiking PCP in soil. The result of Fenton oxidation indicated that H2O2 concentration 206 mM and Fe2+ concentration 57.6 mM were the optimal concentrations for the red soil experiment, the removal efficiency of PCP reached to 75%, however the concentration of H2O2 required to upgrade to 825 mM for alluvial soil in order to obtain 70% removal efficiency. Using 1 mM Cyclodextrin solution to wash PCP from soil, the removal efficiency was 60% for red soil while reach to 80% for alluvial soil. Various temperature, pressure and modifier ratio were conducted in supercritical carbon dioxide extraction experiments. The extraction efficiency reached to 60% in the condition of 100 bar and 70˚C for both soils, moreover the extraction efficiency increased about 10% while 5% (v/v) methanol modifier was introduced, however the extraction efficiency decreased when 10% modifier was overdosed. The extracted PCP was concentrated in the methanol with 2 mL volume, was then examined with Fenton reaction. The data showed the PCP was completely destructed by using significantly lower amount of Fenton’s reagent compared to directly addition of Fenton’s reagent to soil.
Keywords: Supercritical fluid extraction, Soil, Pentachlorophenol, Fenton oxidation, Cyclodextrin.

並列關鍵字

Supercritical fluid extraction ； Soil ； Pentachlorophenol ； Fenton oxidation ； Cyclodextrin

參考文獻

74. 桂椿雄，「超臨界流體萃取法之簡介」，化學，第56卷，第4期，第303-309頁（1998）。

1. Aguado, M. and Anderson, M., Solar Energy Materials and Solar Cells, Vol. 28 (1993).

2. Ajzenberg, N., Trabelsi, F., and Recasens, F., “What’s New in Industrial Polymerization with Supercritical Solvents? A Short Review,” Chemistry Engineering and Technology, Vol. 23, pp. 829-839 (2000).

3. Bishop, D. F, Stern, G. and Fleischman, M.C Hydrogen Peroxide Catalystic Oxidation of Refractory Organics in Municipal Waste Water”, I & EC Process Design and Development, Vol. 7 (1), pp. 110 (1968).

4. Barbeni, M., Minero, C., Pelizzetti, E., Borgarello E. and Serpone, N., “Chemical Degradation of Chlorophenols with Fenton’s Reagent,” Chemosphere, Vol. 16, pp. 2225-2237 (1987).