【摘 要】
：
A batch of column experiments was carried out to investigate the change of Cr(Ⅵ) concentration leached out from chromium-containing slag with HCl as leaching a
【基金项目】
：
国家高技术研究发展计划(863计划)
论文部分内容阅读
A batch of column experiments was carried out to investigate the change of Cr(Ⅵ) concentration leached out from chromium-containing slag with HCl as leaching agent,and to study influences of pH,ratio of solid mass to solution volume,flow velocity and temperature on Cr(Ⅵ) leaching.The optimal parameters were obtained for Cr(Ⅵ) leaching and a fitting model was established to describe the procedure of Cr(Ⅵ) leaching.The results show that Cr(Ⅵ) concentration in leachate increases with decreasing pH and increasing flow velocity and temperature.Moreover,Cr(Ⅵ) leaching percentage increases with increasing ratio of solid mass to solution volume.The optimal parameters for Cr(Ⅵ) selective leaching are as follows:pH=3.0,1:5 of ratio of solid mass to solution volume,180 mL/min of flow velocity and 40 ℃ of temperature.The procedure of Cr(Ⅵ) leaching fits well with the model:v=1.87t-0.54,indicating that the leaching rate of Cr(Ⅵ) declines in an exponential order of-0.54.
其他文献
极移季节变化的地球物理定量激发迄今未得到圆满的解释. 基于大气海洋耦合数值环流模式, 计算了大气和地表水及海洋角动量变化. 与日本气象局(JMA)客观分析资料计算的大气角
Soybean [Glycine max (L.) Merr.] is one of the world’s major crops, and soybean seeds are a rich and important resource for proteins and oils. While “omics”s
Carotene hydroxylases catalyze the hydroxylation of a-and b-carotene hydrocarbons into xanthophylls. In red algae, b-carotene is a ubiquitously distributed caro
Mutants defective in chloroplast development or photosynthesis are liable to accumulate higher levels of anthocyanin in photo-oxidative stress. However, regulat
对我国陕南和滇东旱期骨骼化石研究表明,晚前寒武纪末至早寒武世是地球生物矿化作用急剧变化时期.以Cloudina为代表的晚前寒武纪末骨骼化石,表现出叠锥套合结构,有机质成分高,壳变异大,具明显塑性变形等特征.早寒武世骨骼化石大量涌现,分布广泛,磷质、钙质和硅质骨骼生物群形成.以软体动物为例,早寒武世骨骼化石微细结构出现分异,现生软体动物壳质结构的主要类型柱状结构、交错结构和规则叶片结构已经发育;纤型
末次盛冰期（LGM）是距今最近的一个与现代环境反差最大的气候时期.利用包含较为详细陆面过程的区域气候模式,通过分别加入现代植被和根据花粉化石资料转化的东亚地区LGM古植被,模拟了LGM东亚季风气候并研究了植被变化对LGM东亚季风的影响.由区域气候模拟得到的较为精细的气候演变图像表明:LGM东亚大陆全年降温是导致东亚冬季风强盛、夏季风萎缩的重要原因;夏季西太平洋副热带高压的西伸、加强,是造成中国东部
作者首先阐述了入世凸显医院管理是竞争的关键。一是管理观念的转变 ,充实管理内涵、拓宽管理视野、提升管理高度、改变管理思维、调整管理结构 ;二是现代管理技术的应用。其
在岩石矿物学研究的基础上,测定了我国两个南极陨石、以及光明山和庄河球粒陨石的稀有气体同位素丰度,并根据宇宙成因核素的产率,获得了这4个普通球粒陨石的宇宙射线暴露年龄和气体保存年龄.两个南极陨石的暴露年龄分别为17.0± 2.5Ma（GRV 98002）和0.052±0.008 Ma（GRV 98004）,光明山球粒陨石为68.9±10 Ma,庄河球粒陨石为3.8±0.6 Ma.GRV 98004（
为解决近实时GPS精密单点定位中精密钟差改正问题.在分析现有卫星钟差预报模型的优缺点基础上,将GM(1,1)循环模型拓展进行卫星钟差预报,并提出了一种改进的GM(1,1)-AR(p)钟差预报模型,利用IGS数据中心提供的5分钟标准数据进行短期预报,分析所提改进方法能达到的精度.研究结果表明:改进的卫星钟差预报方法能有效提高钟差预报精度,是可行的.
The thin films of TiO2, doped by Mn or Zn with nonuniform distribution, were prepared by sol-gel method under process control. The actinic absorption of the cat