J. Mater. Sci. Technol. ›› 2011, Vol. 27 ›› Issue (1): 74-80.

• Research Articles • 上一篇    下一篇

Immobilization of Co(II) ions in cement pastes and their effects on the hydration characteristics

EisaEl SAYEDHekal1,Essam A.Kishar2,MahaRabiMohamed3,WafaaSalahHegazi4   

  1. 1. Faculty of Science -Ain Shams University
    2. Ain shams University,Cairo,Egypt
    3. Girl college - Ain Shams University
    4. omen's College for Arts, Science and Education, Ain Shams University
  • 收稿日期:2009-05-14 修回日期:2010-01-30 出版日期:2011-01-28 发布日期:2011-01-30
  • 通讯作者: Essam A.Kishar

Immobilization of Co (II) Ions in Cement Pastes and Their Effects on the Hydration Characteristics

Eisa Hekal, Essam Kishar, Wafaa Hegazi, Maha Mohamed   

  1. 1) Chemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
    2) Chemistry Department, Women0s College for Arts, Science and Education, Ain Shams University, Cairo, Egypt
  • Received:2009-05-14 Revised:2010-01-30 Online:2011-01-28 Published:2011-01-30

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摘要： ABSTRACT The immobilization of Co(II) in various cement matrices was investigated using the solidification/stabilization (s/s) technique. The different cement pastes used in this study were ordinary Portland cement in absence and presence of water reducing- and water repelling-admixtures as well as blended cement with kaolin. Two ratios of Co(II) were used (0.5 and 1.0% by weight of the solid binder). The hydration characteristics of the used cement pastes were tested via the determination of the combined water content, phase composition and compressive strength at different time intervals up to 180 days. The degree of immobilization of the added heavy metal ions is evaluated by determining the leached ion concentration after time intervals extended up to 180 days. The leachability experiments were carried out by using two modes; the static and the semi-dynamic leaching processes. It has been noticed that the concentration of the leached Co2+ ions in the static mode of leachability was lower than the solubility of its hydroxide in all the investigated cement pastes.

Abstract: The immobilization of Co (II) in various cement matrices was investigated by using the solidification/stabilization (S/S) technique. The different cement pastes used in this study were ordinary Portland cement in absence and presence of water reducing- and water repelling-admixtures as well as blended cement with kaolin. Two ratios of Co (II) were used (0.5% and 1.0% by weight of the solid binder). The hydration characteristics of the used cement pastes were tested via the determination of the combined water content, phase composition and compressive strength at different time intervals up to 180 d. The degree of immobilization of the added heavy metal ions was evaluated by determining the leached ion concentration after time intervals extended up to 180 d. The leachability experiments were carried out by using two modes: the static and the semi-dynamic leaching processes. It was noticed that the concentration of the leached Co2+ ions in the static mode of leachability was lower than the solubility of its hydroxide in all the investigated cement pastes.

Key words: Hydration characteristic of cement, Admixtures, Immobilization, Heavy metals