【摘 要】
：
The capture capacity and its mechanism of C-S-H gel to heavy metal ions (Cr, Pb, Zn, Cd, Cu) with different valence and existence form were analyzed by X-ray diffraction analysis, x-ray photoelectron
【机 构】
：
China Building Materials Academy, 100024, China S
【出 处】
：
The 14th International Congress on the Chemistry of Cement (
论文部分内容阅读
The capture capacity and its mechanism of C-S-H gel to heavy metal ions (Cr, Pb, Zn, Cd, Cu) with different valence and existence form were analyzed by X-ray diffraction analysis, x-ray photoelectron spectroscopy,transmission electron microscopy analysis, scanning electron microscopy analysis, toxicity characteristics leaching procedure (TCLP) and other analysis method.Meanwhile, the curing stability of C-S-H gel to heavy metal at 210 days of age were also discussed.The research results showed that the immobilization mechanism and capture capacity of C-S-H gel to heavy metal ions with different valence and existence form were different.The toxicity characteristic leaching procedure (TCLP)was used to evaluate the level of immobilization of heavy metals in C-S-H gel.It was found that the degree of Cd, Zn and Cu ions immobilization was very high (exceeding 99%), while the degree of Cr(VI) immobilization was very weak (about 50%).At the same time, the degree of multi-heavy metal ions immobilization was a little lower than to a single heavy metal ion.A time-series study showed that the immobilization and stability of Cr(VI) and Pb was weak within 210 days of age.In addition, at the hydration liquid phase, the presence of Cr(VI) had a tremendous effect on the immobilization stability of lead at 28 days of age, while Cr(Ⅲ) had less impact on it.There were some differences on the capture capacity of C-S-H gel with different calcium silicon ratio to heavy metal ions.The degree of immobilization of heavy metal ions was reduced under the freezing and thawing, salt chlorine erosion and complex environmental factors condition, and the immobilization of Cr(VI) was the most affected,followed by lead, zinc.
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