| Summary: | 碩士 === 國立屏東科技大學 === 環境工程與科學系 === 87 === The objective of this research is to examine the efficiency of electrokinetic technique on three Cd and Cu spiked soils. The factors studied herein include reaction time, organic matter, conducting solution and soil texture. It was found that applying 16V electric potential could remove Cd and Cu faster than that of 8V. The best reaction time was 30 days. A red-brown ironic oxide precipitate was formed in Yueh-Shyh-Jieh (YSJ) silt clay at 3.6-7.2 cm from anode. For those Cd and Cu spiked Nei-Pu (NP) claand Chang-Shing (CS) silt clay loam, using 0.1N HCl as conducting solution had the best Cd and Cu removal efficiency than in other solutions, e.g. 0.01N HCl and distilled water. Cd in YSJ silt clay had similar electrokinetic removal tendency to Cu. In the experiments of sand addition, for the Cd and Cu spiked NP clay and CS silt clay loam, the Cd and Cu removal efficiency decreased with addition of sand. The sequence of removal efficiency is as follows: contrast >10%>20%>30% sand addition. Cd and Cu removalefficiency in spiked YSJ silt clay had no significant difference in percentage of sand addition. Because peat moss had great specific surface and more exchange site that could reduce the cation migration rate, for
spiked NP clay and CS silt clay loam, the order of Cd and Cu removal efficiency is as follows: contrast >1%>2%>3% peat moss addition. The removal efficiencies of Cd and Cu in smaller experimental scale cell were better than those in larger bench scale cell. Cd removal efficiency of spiked NP clay is smaller cell was higher than that in larger cell. However for Cu spiked NP clay, Cu removal efficiency of larger cell was higher than that in smaller cell. Due to polarization effect, Cd and Cu removal efficiencies of spiked YSJ silt clay in both size cells are similar. As to Cd and Cu spiked CS silt clay loam, it was found that the polarization effect could be overcome after 180 days electrification in larger cell. The removal efficiencies of Cd and Cu in bench-scale cell were satisfactory.
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