| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Research Abstract |
To learn efficiency and safety of washing-reagent-injection, a new soil/groundwater remediation technique for chlorinated organic solvent pollution, the effects of coexisting surfactants and high-molecular-weight organic compounds on the water solubility of trichloroethylene (TCE), the gravity-driven migration behavior of TCE in a glass-bead-packed column, and the reductive dechlorination decomposition of TCE with zerovalent iron powder were investigated.
The effect of reagent type and concentration on TCE solubility and migration behavior in glass-bead-packed columns appeared severally each other. Several of the surfactants drastically increased the solubility of TCE, but some surfactants and the high-molecular-weight organic compounds had no effect on TCE solubility. The migration behaviors of undiluted TCE in the washing-reagent-saturated columns differed substantially for the tested chemicals. Some of the surfactants introduced rapid gravity-driven migration over a wide range of con
… More
centrations.
During the dechlorination reaction, the amount of TCE decreased, and the formation of cis-1,2-dichloroethylene was observed. The decomposition of TCE was found to be first order with respect to the-TCE and zerovalent iron concentrations when the solution contained no additives. The rates of decomposition of TCE in the presence of the additives were lower than the rate in the absence of the additives: the rate constant was reduced by a factor of 0.7 for the cationic surfactant cetyltrimethylammonium bromide; by a factor of 0.5 for the anionic surfactants sodium n-dodecylbenzenesulfonate, sodium n-dodecylsulfate, and sodium n-dodecanesulfonate and for the high-molecular-weight organic compounds soluble starch, β-cyclodextrin, and polyethyleneglycol 6000;and by a factor of 0.2 for sodium laurate and the nonionic surfactants Triton X-100,Tween 20,Tween 60,Brij 35,and Brij 58.
The results indicate that the washing-reagent-injection method contains several advantages and disadvantages. Importance of thoroughly assessment for several factors is suggested for the practical use of this technique Less
|
