為有助於未來河川底質環境監測時，快速推估孔隙水中重金屬濃度，因此建立重金屬在底泥顆粒和孔隙水間的分佈係數Kd(partition coefficient)實有其必要性。另為瞭解及推估重金屬在底泥顆粒及週遭孔隙水間的傳輸現象受環境因子之影響，本研究以二仁溪受嚴重重金屬污染之底泥為例進行試驗。結果顯示，不同深度及不同採樣點獲得之底泥樣品，經分析計算後得到之分佈係數Kd值大小變化關係為銅＞铬＞鉛＞镍＞鋅。分佈平衡係數kD愈小，代表重金屬愈易釋出，鋅及镍比鉛及铬更易於釋出到孔隙水中，而銅最不易釋出到孔隙水中。底泥顆粒中鐵氧化物含量和銅及鋅之分佈係數成正相關(r=0.61及0.50)。除與錳氧化物鍵結態之銅量外，銅之四種鍵結態量(易交換態、與碳酸鹽鍵結態、與鐵氧化物鍵結態、及與有機物鍵結態)和分佈係數成明顯之正相關(r=0.73、0.57、0.62及0.66)。 To quickly analyze the concentration of heavy metals in pore water for routine measurement of sediment quality. It is necessary to establish the partition coefficient of heavy metals between sediment particles and pore water. Another focus of this study is to realize and estimate the diffusion phenomena of heavy metals affected by the environmental parameters. For example, the contents of carbonates, iron-oxides, manganese-oxides, organic matter existed in sediment particles, and the concentration of heavy metals bound to five fractions. The results showed that the order of magnitude for partition coefficient of metals was Cu＞Cr＞Pb＞Ni＞Zn，in spite of the sediments were collected from different sites and depth. The lower the partition coefficient existed, the more easily the remobilization of heavy metals from sediment particles occurred. Zn and Ni were more easily to remobilize to the pore water than Pb and Cr. Cu was the most hard to remobilize to pore water in this study. The correlation between iron-oxides content and partition coefficient of Cu and Zn was positive significant (r=0.61 and 0.50). The concentration of Cu, found in phases of exchangeable, carbonates, Fe-oxides and organic matters have positive significant correlation with partition coefficient (r=0.73、0.57、0.62 and 0.66).
