title: Geomaterials: their application to environmental remediation.
abstract: Geomaterials are materials inspired by geological systems originating from the billion years long history of the Earth. This article reviews three important classes of geomaterials. The first one is smectites-layered silicates with a cation-exchange capacity. Smectites are useful for removing pollutants and as intercalation compounds, catalysts and polymer nanocomposites. The second class is layered double hydroxides (LDHs). They have an anion-exchange capacity and are used as catalysts, catalyst precursors, sorbents and scavengers for halogens. The third class of geomaterials is zeolites-microporous materials with a cation-exchange capacity which are used for removing harmful cations. Zeolite composites with LDHs can absorb ammonium and phosphate ions in rivers and lakes, whereas zeolite/apatite composites can immobilize the radioactive iodine. These geomaterials are essential for environmental remediation.
authors.affiliation: Environmental Remediation Materials Unit, National Institute for Materials Sciences, Namiki 1-1, Tsukuba, 305-0044, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Environmental Remediation Materials Unit, National Institute for Materials Sciences, Namiki 1-1, Tsukuba, 305-0044, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tamura
authors.affiliation: Advanced Materials Science Research and Development Center, Environmental Research Institute, Kanazawa Institute of Technology, Yatsukaho 3-1, Hakusan, Ishikawa, 924-0838, Japan.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Environmental Remediation Materials Unit, National Institute for Materials Sciences, Namiki 1-1, Tsukuba, 305-0044, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Iyi
authors.affiliation: Department of Functional Material Science, Graduate School of Science and Engieering, Ehime University, Bunkyo-cho 2-5, Matsuyama, 790-8577, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Morimoto
keywords: LDH; apatite; geomaterial; remediation; smectite; zeolite