本研究之目的是藉由調整受污染之土壤於皂素溶液中之pH、皂素濃度、振盪時間、曝氣流量等變因，以探討土壤重金屬去除率之控制參數。
調整土壤與皂素溶液pH為6時，在150rpm振盪24小時可達平衡。在振盪操作模式下，對土壤中重金屬Ni2+、Cu2+、Cr3+移除率，隨皂素濃度增加而提高，但達某一濃度時，移除率將不再提升。要達最佳Ni2+、Cu2+、Cr3+去除率之皂素濃度分別為7000、7000以及30000 mg/L。在此條件下Ni2+、Cu2+、Cr3+之去除率分別為88.6 %、29.1 %、19.1 %。
在曝氣操作模式下，控制流量7 ml/min及pH 6時，可得最多之皂素泡沫產生量。經曝氣28分後，對土壤重金屬Ni2+、Cu2+、Cr3+之去除率，分別為84.5 %、52.1 %、25.2 %。
以上結果顯示，曝氣操作28分即可達成最大量之土壤重金屬去除率，但振盪操作則需24hr才能達到相同之效果。 The purpose of this study is to get the best removal of heavy metals from a contaminated soil in the presence of saponin solution by adjusting pH, saponin concentration, vibration time and aeration rate.
Results showed that the equilibrium time of soil and saponin solution could be reached in 24 hrs by using vibration method at 150 rpm and pH=6. By using the above conditions, the removal efficiency of heavy metals increased with the saponin concentration. However, the removal rate reached its maximum at a specific concentration of saponin. Controlling saponin solution at 7000、7000 and 30000, the maximum removal of Ni2+、Cu2+ and Cr3+ were 88.6%、29.1% and 19.1%, respectively.
The best form formation of saponin solution could be obtained by controlling aeration rate at 7 ml/min and pH at 6. Results showed that the best removal of Ni2+、Cu2+ and Cr3+ could be reached in 28 min and their removal percentages were 84.5、52.1 and 25.2, respectively.
The above results showed that aeration method took only 28 min to achieve the maximum removal of heravy metals from a contaminated soil but 24 hrs would be needed for vibration method to obtain the same desorption effect.
