摘要
采用硅酸和纯CaO人工合成不同n(Ca)/n(Si)值的水化硅酸钙,利用合成的CSH与Na2CrO4溶液进行一系列的吸附反应.实验结果表明:所有n(Ca)/n(Si)值的CSH对CrO42-的俘获量都不大,因此在利用水泥固化处理含Cr(Ⅵ)污染物过程中,CSH对Cr(VI)的固化作用很有限;2 0℃时低n(Ca)/n(Si)值的CSH对CrO42-的吸附量比8 0℃时的略高,但温度对高n(Ca)/n(Si)值的CSH的吸附性几乎不产生影响.n(Ca)/n(Si)值为1.6的CSH在含Cr(VI)液相中形成时,对液相中的Cr(Ⅵ)有一定的吸附作用,但已形成的CSH对液相中的Cr(Ⅵ)吸附量比较小;n(Ca)/n(Si)为1.6的CSH对CrO42-的吸附在10 m in内可达到平衡,且所吸附的CrO42-全被石灰水中浓度不高的OH-所置换,故该吸附为晶格外吸附.
Calcium silicate hydrate （CSH） with different n（ Ca）/n（Si） were synthesized by silicic acid and quicklime. After CSH synthesis, a series of adsorption experiments of chromate binding onto synthetic CSH were carried out and showed that the capacity of chromate adsorbed by CSH at all n（ Ca）/n（Si） is not obvious , indicating that CSH is not an important role in cement-based solidification/stabilization of chromate-containing waste. The quality of the adsorption of chromate on CSH at low n （Ca）/n （Si） under 20 ℃ is a little greater than that under 80 ℃. Relatively, the temperature has little effect on CSH at high n（ Ca）/n（Si）. As for CSH at n （Ca）/n （Si） of 1.6, its capacity to entrap chromate is limited during formation. But after it is formed, CSH capacity to adsorb chromate increases . The adsorption of chromate on CSH at n（Ca）/n（Si） of 1.6 can reach equilibrium within ten minutes, but the chromate bound on CSH can be replaced by OH-from Ca（ OH）2 solution, indicating that chromate is bound outside the lattice of CSH during the adsorption process.
出处
《桂林工学院学报》
北大核心
2006年第2期263-267,共5页
Journal of Guilin University of Technology
基金
国家杰出青年科学基金资助项目(40425001)
关键词
水化硅酸钙
合成
吸附
铬酸盐
calcium-silicate-hydrate
synthesis
adsorption
chromate
