粉煤灰硬化体中Cr(Ⅵ)的渗滤溶出行为(英文)

PERCOLATION LEACHING BEHAVIOR OF Cr(Ⅵ) FROM CEMEN-TSOLIDIFIED FYL ASH

模拟雨水通过土壤的渗滤过程,进行了粉煤灰硬化体渗滤溶出试验。研究了外界水渗透通过粉煤灰硬化体时,其中可溶性Cr(Ⅵ)在硬化体、土壤、渗滤液中的迁移转换规律,评估了粉煤灰硬化体中Cr(Ⅵ)的溶出及其对土壤和地下水可能产生的影响。结果表明:水渗透通过粉煤灰硬化体时,会将其中部分的Cr(Ⅵ)带出,转移到土壤和渗滤液中;渗滤液中Cr(Ⅵ)的累计量与时间的对数呈线性增加关系,Cr(Ⅵ)的溶出过程主要受扩散控制;渗滤后体系中可溶性Cr(Ⅵ)总量显著减少,说明Cr(Ⅵ)在从硬化体向土壤和渗滤液中的迁移过程中还存在着形态的变化。灰色关联分析表明:溶出过程中,Cr(Ⅵ)的溶出与Ca2+和Na+的溶出有较密切的相关性。

A percolation leaching test was carried out on cement-solidified fly ash specimens to simulate the case of rain penetrating into them, then into soil and finally into groundwater. The transportation and transformation of dissolvable Cr（Ⅵ） among the specimen, soil and leachate during the process were investigated. The impact of dissolvable Cr（Ⅵ） in fly ash on soil and groundwater was evaluated based on the above tests. The results show that： the Cr（Ⅵ） in the specimens could leach out and some was retained in the soil as water penetration occured; the Cr（Ⅵ） concentration in the leachate was increased with time according to the logarithm, which indicates that it is a diffusion-controlled leaching process; after the leaching test the total amount of dissolvable Cr（Ⅵ） in the system was much decreased, which means during the process Cr（Ⅵ） had undergone a transformation of valence or species. The leaching of Cr（Ⅵ） from the specimens was closely related to the leaching of Ca2＋ and Na＋ in the specimens, according to the result of gray incidence analysis.