多環芳香烴在不同土壤中的傳輸及整治

Transportation and Remediation of PAHs in Different Soils

黃啟南(Chi-Nan Huang)

指導教授 ： 泣奉華

崑山科技大學/工程學院/環境工程研究所/碩士(2005年)

摘要

本研究探討二種多環芳香烴（PAHs）在不同有機質含量的飽和層土壤的傳輸，並以地下水、humic acid、非離子性界面活性劑Tween 80 、Triton X-100進行整治（研究所採用之污染物PAHs屬於非離子性有機化化合物，而非離子型界面活性劑與其他型界面活性劑相比，對非離子性有機化化合物具有較高之脫附效率及對環境之低污染負荷。所以採用非離子型界面活性劑：Tween 80 與 Triton X-100 作為脫附液。）。研究中將以naphthalene和anthracene 作為PAHs 的代表，實驗主要分兩部份進行（1）靜態管柱實驗（２）連續流動式管柱穿透實驗（模擬污染物在地下水中的實際傳輸），在一定的溫度、流速條件下，瞭解PAH在土壤中的吸附和脫附反應，並脫附可行性研究，作為後續實場整治的重要依據，管柱實驗可以更具體的模擬污染物在地下水中流動的真實動力情況，改善以往多著重於以燒杯方式進行平衡反應的研究。
以humic Acid作為脫附液時，在動態連續流實驗中，其對naphthalene的脫附效果似乎與硝酸鈉溶液無太大之差別。但對anthracene的脫附，則有較明顯之脫附效果(脫附率>21%)。
而以非離子性界面活性劑對已經過PAH吸附穿透之土壤進行脫附，不管是裕農土或崑山土對naphthalene或anthracene的脫附率均能大於55% (Anthracene穿透崑山土後施用Tween 80脫附之實驗)，但受限於其吸附濃度較低，使得溶解度增加有限。而當對高濃度500（mg/kg）PAH污染之土壤進行脫附時，最高可增加30倍之溶解度。
本研究以管柱實驗具體證明非離子界面活性劑能用於受疏水性污染物影響之土壤的整治，而對疏水性較高的anthracene，其脫附效果也較明顯高於僅使用一般或含有機質的地下水的脫附成效。管柱實驗中曾遇瓶頸，所使用的界面活性劑會造成管柱孔隙的阻塞，其原因可能為土壤中的膠體因界面活性劑而脫離附著之顆粒，故在實驗中為了兼顧整治效率，但又不致造成孔隙阻塞，所使用之Tween 80的濃度為0.1%，Triton X-100為0.1%。此問題亦是實場整治之重要考量。

關鍵字

污染物傳輸 ； 多環芳香烴 ； 污染整治 ； 管柱實驗

並列摘要

The focus of this research is on the transportation of PAHs in different soils. Three nonionic surfactants such as natural organic matter (NOM)﹐Tween 80﹐Triton X-100﹐will be separately and sequentially used to investigate the remediation efficiencies of PAHs contaminated soils.
Experiments are devided into two parts﹐including the static column experiments﹐and the continuous-flow column experiments which is design to simulate the contaminant transportation in real groundwater. The flushing solutions of surfactants were performed under the condition of fixed temperature and flow rate. The relationships between solid phases and different solutes will be investigated thoroughly to find the best remediation condition to be used in contaminated sites.
When humic acid was used as the desorbing solution, there is no great difference compared to that of sodium nitrate to desorbed naphthalene from soils﹐but have obvious result in desorbing anthracene (desorb rate＞21％).
If the two nonionic surfactants were used as desorbing solution﹐it showed more than 55% of removing efficiencies of anthracene and naphthalene in both Yu-long soil or Kun-shan soil. Since the concentrations of anthracene and naphthalene in the soils were low, the increases of the solubilities were limited. When the desorption experiments were done using the contaminated soils of 500 mg/g of PAHs, the apparent solubility can increase up to 30 times,
Column experiments were adopted to understand the availability of using nonionic surfactants to remediation real site PAHs contaminated soil. For anthracene which has a higher hydrophobicity than naphthalene showed higher desorption efficiency than that of using only groundwater or humic acid solution. We also found that the surfactants caused the mobility of colloids from the particles, and resulted the clog of column. In the research, the optimal concentrations of Tween 80 and Triton X-100 are 0.1%, it can have good removing efficiencies for PAHs contaminated soils and will not resulte the clogging of soil column. The movement of colloids should be noticed in the application of surfactants to field remediation.

並列關鍵字

pollution remediation ； contaminate transportation ； column experiment ； PAHs

參考文獻

[6]Chiou,C.T., Porter,P.E. & Schmedding,D.W. Partition Equilibria of Nonionic Organic Compounds between Soil Organic Matter and Water. Environ. Sci. Technol. 17, 227-231,1983

[8]Chiou,C.T., Malcolm,R.L., Brinton,T.I. & Kile,D.E. Water Solubility Enhancement of Some Organic Pollutants and Pesticides by Dissolved Humic and Fulvic Acids. Environ. Sci. Technol. 20 ,502-508 (1986).

[9]Karickhoff, S.W., Brown, D.S. Sorpton of Hydrophobic Pollutants on Nautral Sediments. Water Search, 13, 241-148 (1979).

[15]Chan, L.C., Lee, J.J., Park J.W. , Solubilization of PAH mixtures by three different anionic surfactants, Environmental Pollution 118,307-313 (2002)

[17]Dianne J. Luning P., Parmely H. Solubilization of polycyclic aromatic hydrocarbon mixtures in micellar nonionic surfactant solutions. Water Research 36,3463–3472 (2002)