草酸促进双酚A在黏土矿物悬浮液中光降解研究

选择两种常见的天然黏土矿物高岭石和蒙脱石,研究了有机污染物双酚A(BPA)在其表面的吸附及草酸对黏土矿物悬浮液中BPA光降解的影响.结果表明,BPA在两种黏土矿物表面的吸附量较小,吸附符合Langmuir等温式.在250W金属卤化物灯(λ≥360nm)照射下,草酸可显著促进BPA在高岭石和蒙脱石悬浮液中的光降解,降解动力学符合Langmuir-Hinshelwood方程. 降解速率受pH值的影响较大,pH=4.0时速度最快,光降解速率同时受草酸浓度的影响.最后,通过分析矿物中铁的化学环境及反应过程中铁浓度变化,分析了草酸促进BPA在黏土矿物悬浮液中光降解的可能机制.     

某枪用铝合金阳极氧化膜变色行为及对策研究

为了提高某枪外观性能,解决机匣在使用过程中的变色问题,对机匣铝合金阳极氧化原工艺、改进工艺进行了环境试验研究、环境适应性评价.针对枪械的使用环境,主要选择江津和万宁试验站户外暴露的试验方式及实验室模拟环境加速试验的方法研究铝合金机匣耐光性及变色原因.试验结果显示,原有机着色工艺耐光性较差,其变色的主要原因是光辐射作用使膜内着色有机染料的主要发色基"一N-N一"发生了断裂,而改进的金属盐电解着色工艺在试验中未发生变色,能有效解决铝合金机匣的变色问题.     

Adsorption characterizations of fulvic acid fractions onto kaolinite

Fulvic acids extracted from a typical rice-production region near Taihu Lake of China were fractionated into three fractions including F4. 8, F7. 0 and F11. 0(eluted by pH4. 8 buffer, pH 7. 0bufferandpH 11. 0buffer, respectively). Sorption of fulvic acid(FA)fractions onto kaolinite was studied by batch adsorption experiments, and characterizations of kaolinite before and after adsorption were investigated using scanning electron microscopy(SEM). Adsorption isotherms of kaolinite for three FA fractions fit well with the Langmuir adsorption model. The adsorption density of the three fractions was positively correlated with the ratio of the amount of the alkyl carbon to that of carboxyl and carbonyl carbon in FA fractions and followed an order of F11. 0>F7. 0>F4.8.Hydrophobic interaction Was one of the control mechanisms for the sorption of FA fraction onto kaolinite. SEM images confirmed that compared to blank kaolinite samples, kaolinite samples coated by a FA fraction displayed an opener and more dispersed conformation resulting from the disruption of the floe structure in complex. Dispersion of kaolinite after adsorption was due to the repulsion between negatively charged FA. coated particles, which is closely related to the amount of FA fractions absorbed on kaolinite.     

硬质玻璃容器保存微量铅元素水样的实验

玻璃容器材质中一般含有少量金属元素。使用玻璃容器保存微量金属元素水样时就可能会污染水样，文中以铅元素为例，针对硬质玻璃容器用2种不同的清洗方法对保存水样的影响情况进行实验对比。     

精喹禾灵在高岭土和蒙脱石中的吸附行为

采用批量平衡实验,研究了精喹禾灵在蒙脱石和高岭土中的吸附行为及作用机理.结果表明,精喹禾灵在这两种供试黏土矿物中的吸附过程分为快速吸附、慢速吸附和吸附平衡3个阶段,吸附平衡时间都约为12 h;Langmuir模型能较好地描述其在两种供试黏土矿物中的吸附行为;蒙脱石和高岭土对精喹禾灵的最大吸附容量的关系为蒙脱石>高岭土;傅立叶变换红外光谱以及X-射线衍射分析显示,在吸附过程中精喹禾灵分子进入了蒙脱石层间,而未进入到高岭土层间;蒙脱石主要是通过其层间结构对精喹禾灵进行吸附,而高岭土则主要是通过硅氧外表面发生吸附,其吸附作用力主要是氢键.     

pH对粘土矿物胶体在饱和多孔介质中运移的影响

环境pH值条件的变化是影响土壤胶体运移的重要因素之一.本文选取土壤体系中常见的两种不同结构类型的粘土矿物胶体高岭石和蒙脱石作为主要实验材料,通过室内模拟实验和数学模型分析的手段,分别研究了不同pH值条件下,两种无机胶体在多孔介质中的迁移规律.结果表明:高岭石胶体受溶液的pH条件影响强烈,随着pH的变化,ξ电位及颗粒粒径大小发生明显变化,不同的pH条件下的穿透曲线差异明显.在酸性条件下,高岭石胶体回收率显著降低,而蒙脱石胶体基本不受pH影响;利用HYDRUS-1D模型拟合结果与测定数据之间非常匹配,说明利用该模型模拟饱和条件下胶体在多孔介质中的迁移完全可靠.