Permeability characteristics of Lake Kojima sediment and their improvement

Munehide Ishiguro, Ryouichi Iwamoto, Akiko Hamabe, Tomoyuki Ishida, Takeo Akae

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

As lake sediments are one of the causes of eutrophication, their removal and effective use has been considered. When they are used as soil in a land, proper permeability is required. However, soil permeability has not completely been understood due to diversity of clays and organic compounds. We clarified permeability characteristics of Lake Kojima sediment, nonswelling clayey soil, by measuring saturated hydraulic conductivity (K). A decrease in K during percolation of dilute electrolyte solution was small when Ca was adsorbed by the soil; K became 3.4×10-5 cm/s at pH 5, 2.9×10 -6 cm/s at pH 7, 7.5×10-6 cm/s at pH 9, and 2.3×10-5 cm/s at pH 11 after pure water percolation. Although the permeability tended to decrease as pH increased, K at pH 11 became larger than that at pH 9 due to chemical reaction between soil particles and Ca. On the other hand, when Na was adsorbed, K drastically decreased with pH increase; K became 7.1 ×10-6 cm/s at pH 5, 3.1 × 6 cm/s at pH 7, 1.7×10'7 cm/s at pH 9, and 1.3×10-7 cm/s at pH 11 after pure water percolation. The obtained results could be explained qualitatively by the theory. Next, an improvement method of permeability of Lake Kojima sediment with hydrated lime and gypsum were investigated. Three application methods were compared in the saturated hydraullc conductivity experiment; mixing, surface distribution and solution infiltration. Hydrated lime application with mixing maintained high hydraulic conductivity. The soil structure was supposed to be stabilized by chemical reaction between soil and heterogeneously distributed hydrated lime. On the other hand, gypsum application with solution infiltration maintained the same hydraulic conductivity as that of hydrated lime application with mixing. In that case, electrostatic adsorption of Ca was considered to generate flocculation and kept high permeability.

Original languageEnglish
Title of host publicationContaminated Sediments
Subtitle of host publicationEvaluation and Remediation Techniques
PublisherAmerican Society for Testing and Materials
Pages119-126
Number of pages8
Edition1482
ISBN (Print)0803134088, 9780803134089
Publication statusPublished - Jan 1 2006
Event3rd International Symposium on Contaminated Sediments - Shizuoka, Japan
Duration: May 23 2006May 25 2006

Publication series

NameASTM Special Technical Publication
Number1482
ISSN (Print)0066-0558

Other

Other3rd International Symposium on Contaminated Sediments
CountryJapan
CityShizuoka
Period5/23/065/25/06

Keywords

  • Ca
  • Na
  • Saturated hydraulic conductivity
  • Sediment
  • pH

ASJC Scopus subject areas

  • Engineering(all)

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  • Cite this

    Ishiguro, M., Iwamoto, R., Hamabe, A., Ishida, T., & Akae, T. (2006). Permeability characteristics of Lake Kojima sediment and their improvement. In Contaminated Sediments: Evaluation and Remediation Techniques (1482 ed., pp. 119-126). (ASTM Special Technical Publication; No. 1482). American Society for Testing and Materials.