Experimental study on the remediation of contaminated soils by freezing and thawing

冻融修复污染土壤的实验研究

• 批准号: 14550502
• 负责人: ITO Yuzuru
• 金额: $ 2.18万
• 依托单位: Setsunan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550502/
• 关键词: Contaminated soils; Freezing and thawing; Hydraulic conductivity; Solute transport; Frost heave; 凍結

The purpose of the research is to clarify the applicability of the remediation technology of the contaminated soils by freezing and thawing. In this research, the followings topics were examined: Movement of the water-soluble pollutant by the freezing condition, types of the soil, etc.In the 2002 fiscal year, cooling rate, temperature gradient, effect of the load, and the water supply conditions were examined for cohesive frost susceptible soils.From the experimental result, it was observed in all test conditions that the solute was moved to the cold side from the high temperature side in all conditions. From this fact, the direction of the moisture and solute transport in the freezing frost susceptible soils seem to be generally to the cold side from the high temperature side.In the 2003 fiscal year, the washing technique which based on increase of the hydraulic conductivity of cohesive soil after thawing was examined. Especially, the experiment focus is on the influence of the type of soils and loads in the change of the hydraulic conductivity.The main results are as follows. First, in the series of the experiments, the increase of hydraulic conductivity after freezing and thawing was observed in the range to 100kPa. Next, there is a large difference in the change of the hydraulic conductivity in the types of soils. The hydraulic conductivity increased to several hundred times in Kanto loam, and to about 10 times in Fujinomori clay. Especially, in case of the Kanto loam, the hydraulic conductivity increased to 10^<-3>cm/s to 10^<-4>cm/s that is the value of sandy soil, though hydraulic conductivity in the unfrozen condition is in the range between 10^<-6>cm/s to 110^<-7>cm/s that is the value of cohesive soil. In addition, the hydraulic conductivity differed even in equal void ratio in before and after of freezing and thawing.

研究目的是明确污染土壤冻融修复技术的适用性。在这项研究中，研究了以下主题： 冻结条件、土壤类型等造成的水溶性污染物的移动。 2002 财政年度的降温速度、温度梯度、负荷影响和供水从实验结果来看，在所有测试条件下都观察到溶质在所有条件下都从高温侧移动到冷侧。由此看来，易冻霜土壤中水分和溶质的输送方向似乎总体是从高温侧向冷侧移动。2003财年，基于增加导水率的冲洗技术被采用。检查解冻后的粘性土壤。特别是，实验重点研究了土体类型和荷载对导水率变化的影响。主要结果如下。首先，在一系列实验中，观察到冻融后水力传导率在100kPa范围内增加。其次，不同土壤类型的导水率变化存在较大差异。关东壤土的水力传导率增加到数百倍，藤森粘土的水力传导率增加到约10倍。特别是，在关东壤土的情况下，虽然未冻结条件下的导水率在10^<-6>cm/s 到 110^<-7>cm/s 之间的范围是粘性土壤的值。另外，即使孔隙率相同，冻融前后的导水率也不同。

项目成果

Fujio Tsuchiya, Yuzuru Ito, Kimitoshi Ryokai: "Soil freezing and geotechnical engineering, 7.Ground freezing by cold climate"Journal of the Japanese Geotechnical Society. Vol.51, No.9. 39-45 (2003)

土屋富士夫、伊藤雄、良开公俊：“土壤冻结与岩土工程，7.寒冷气候下的地面冻结”日本岩土工程学会杂志。

伊藤譲, 嘉門雅史, 鳩裕幸: "凍結融解現象を利用した地盤洗浄の可能性"材料. 51巻・1号. 42-45 (2002)

Joe Ito、Masashi Kamon、Hiroyuki Hato：“利用冻融现象进行地面清洁的可能性”材料，第 51 卷，第 1. 42-45 期（2002 年）。

Ito, Y., Kamon, M., Hato, H.: "Remediation of Contaminated Grounds by Soil's Ice Segregation Phenomena"Proc., Fourth International Congress on Environmental Geotechnics. 859-863 (2002)

Ito, Y.、Kamon, M.、Hato, H.：“土壤冰隔离现象修复污染地面”，第四届国际环境岩土工程大会。

土谷富士夫, 伊藤譲, 了戒公利: "土の凍結と地盤工学 7.寒さ利用による地盤凍結"土と基礎. Vol.51,No.9. 39-45 (2003)

Fujio Tsuchiya、Joe Ito、Kimitoshi Ryokai：“土壤冻结和岩土工程 7. 寒冷天气导致的地面冻结”《土壤与基础》第 51 卷，第 39-45 期（2003 年）。

Yuzuru Ito, Masashi Kamon, Hiroyuki Hato: "A laboratory experiment to investigate the applicability of Freezing and thawing method for remediation of Contaminated Ground"Journal of the Society of Material Science, Japan. Vol.51, No.1. 42-45 (2002)

Yuzuru Ito、Masashi Kamon、Hiroyuki Hato：“研究冷冻和解冻方法修复污染地面的适用性的实验室实验”日本材料科学学会杂志。