【作者】 李世勇；

【导师】 张成江； 倪师军；

【作者基本信息】 成都理工大学 ， 地球化学， 2007， 硕士

【摘要】 伴随着汞的多用性，汞的环境问题越来越受人关注，尤其在城市这个比较脆弱的生态系统中更为显著，在大气、水体、土壤等生命赖以生存的环境介质中，汞的含量均比较高，甚至超出生命的承受力，严重影响人类的生活质量。因此，对汞在环境中的迁移、转化、释放及其形态研究一直是人们研究的热点问题。论文以成都市市区“网眼”土壤为研究对象，采用化学分析与仪器分析相结合的方法在成都市800℃热释汞分布特征的基础上，对不同温度下土壤汞的释放形态进行研究，取得的主要成果如下：1．城区土壤热释汞含量大小顺序为：建筑区＞公园区＞河流沿岸区，一环路之内＞一环路到二环路之间＞二环路到三环路之间。2．100℃热释后，各形态含量大小顺序为：王水溶态＞碱溶态＞硝酸溶态＞酸溶态、水溶态释放完全；150℃～350℃热释后，各形态含量大小顺序为：王水溶态＞碱溶态＞硝酸溶态，酸溶态、水溶态释放完全；500℃～800℃热释后，各形态含量大小顺序为：碱溶态＞王水溶态＞硝酸溶态，酸溶态、水溶态释放完全。3．根据形态分析数据可知，各形态释放趋势为：水溶态汞在100℃左右基本释放完全，酸溶态汞在150℃左右基本释放完全，碱溶态汞在整个测试过程(50℃～800℃)中释放趋势呈先降低后升高再降低趋势，王水溶态低温时基本没有释放，在350℃左右释放量突然升高，至500℃后释放程度保持平稳。低温(常温～150℃)下，土壤汞热释形态主要以碱溶态为主，水溶态汞以及酸溶态汞释放完全，其主要为硝酸汞、有机汞等；中温(250～500℃)，释放形态主要以王水溶态汞为主，其主要为硫化汞、氧化汞等；高温800℃，释放形态为王水溶态及碱溶态汞，其主要为硫化汞等。4．50℃下土壤热释汞与100℃、800℃两个分析温度热释汞的相关性比较差，100℃与800℃两个温度相关性比较高，呈显著相关关系。更多还原

【Abstract】 Humen beings are paying more and more attention to the mercury enviromental problem, as the mercury is widely used in most fields. Especially in the city ecology system which is frail, the mercury contents in the media such as atmosphere, water, soil is much high, even exceed the level which the life can bear and seriously affect the standerd of living. So the study on the moving, changing, releasing and different formations of mercury is attracting more and more people to study.The thesis is researching on the exposed-soil in Chengdu city, based on the researches on the distribution of the thermal releasing mercury under 800℃, researching on the releasing formations of different tempreture, and making the following conclusions:1) The content order of the thermal releasing mercury in Chengdu urban soil is as follows: the resident area＞the garden area＞the riverine area; the first circle road＞the first to second circle road＞the second to third circle road. The result taking the thermal releasing mercury way to analyse the content and contribution trend is similar to taking the chemical way, which can prove the applicability of this way.2) Under 100℃thermal releasing, the formation order is as follows: the residual＞the alkali soluble＞the nitric acid soluble＞the acid soluble, and water soluble is completely released. Between 150℃to 350℃, the order is: the residual＞the alkali soluble＞the nitric acid soluble, the acid soluble and water soluble are completely released. Between 350℃to 800℃, the formation order is: the alkali soluble＞the residual＞the nitric acid soluble, the acid soluble and water soluble are completely released.3) According to the analysis, the trend of different formation is: the water solution is completely released in 100℃; The acid soluble is completely released in 150℃; The content of alkali soluble is increasing first, then decreasing and increasing later; The content of residual is no changing in lower tempreture, and suddenly decreasing when tempreture is about 350℃, then keep banlance in 500℃. In lower tempreture（the normal tempreture to 150℃）, the main releasing formation is residual and the main compounds are Hg（NO₃）₂ and organic mercury; In middle tempreture （250℃-350℃）, the main releasing formation is alkali soluble and the main compounds are HgS and HgO and so on; In higher temperature the main releasing formation is residual and the main compounds are HgS and so on.4) The relativity of the thermal releasing mercury in 50℃is lower with that in 100℃and 800℃, the later two temperature is too similiar and take on obvious relativity.更多还原