【作者】 韩春芳；

【导师】 侯贤灯；

【作者基本信息】 四川大学 ， 分析化学， 2006， 硕士

【摘要】 纳米二氧化钛催化光诱导冷蒸气发生(PI-CVG)所生成的产物通过气液分离器进行分离后,将气体导入原子荧光光谱仪中进行测定。在本工作中,低分子量的醇(甲醇、乙二醇、1, 2-丙二醇、丙三醇)、醛(甲醛、乙醛)或酸(乙酸、乙二酸、丙二酸)在紫外光的照射下,可将水溶液中的Hg2+还原成Hg0。实验结果表明,纳米TiO2的加入可提高PI-CVG体系测汞的灵敏度。本文详细优化了实验条件,并且在最佳条件下测定了以上九种体系的工作曲线,方法检出限为0.02～0.04μg/L。本文还考察了过渡金属离子Cu2+、Co2+、Ni2+对该体系的干扰情况,结果发现,10 mg/L的Cu2+,50 mg/L的Co2+,100 mg/L的Ni2+对5μg/L Hg2+的测定不产生显著的干扰。另外,还测定了这九种体系分别在加纳米TiO2和不加纳米TiO2条件下的发生效率,初步讨论了PI-CVG体系的发生机理。本文测定七种水样中汞的含量。其中有两种水样计算了其回收率,结果发现:回收率在90%～115%之间。另外五种水样还用原子吸收光谱法进行了结果对照,实验表明:两种方法的结果一致。环境废水中通常含有重金属元素、各种有机物及其衍生物。本文利用该法处理了模拟废水。模拟废水由低分子量的醇、醛、酸以及汞组成。在光照不同的时间后,经过气液分离,测定废液中残余的汞的浓度,计算降解效率。结果表明:模拟废水在紫外光照射6小时之后,汞的降解接近100%。更多还原

【Abstract】 Photo-induced chemical/cold vapor generation (PI-CVG) system was used to produce mercury cold vapor, which was determined by atomic fluorescence spectrometry after gas/liquid separation. Under the UV radiation, Hg2+ in aqueous solution can be converted into Hg0 cold vapor by using an organic reactant of low molecular weight alcohols, aldehydes or carboxylic acids, namely, methanol, formaldehyde, acetaldehyde, glycol, 1,2-propanediol, glycerol, acetic acid, oxalic acid or malonic acid. It was found that the presence of nano-TiO2 nanoparticles (nano-TiO2 later) enhanced the efficiency of the PI-CVG system.Under the optimized experimental conditions, the limits of detection (based on three standard deviation of 11 measurements of a blank solution) were around 0.02 to 0.04μg/L, with linear dynamic ranges up to 15μg/L. Also discussed in detail were the interference of transition metals, generation efficiency in above mentioned nine systems and the mechanisms of the PI-CVG system. Preliminary analytical application of the PI-CVG-AFS revealed that it was very promising for water analysis for ultra low level of mercury. Besides, the nano-TiO2 enhanced PI-CVG can be potentially useful for the disposal of mercury-polluted wastewater in the environmental area. The degradation efficiency of mercury (100 ? g/L) with a simulated wastewater approached 100% after 6 hours.更多还原