攀枝花市大气降尘地球化学特征研究

发布时间：2018-05-05 14:55

本文选题：大气降尘 + 攀枝花　；参考：《成都理工大学》2017年硕士论文

【摘要】：大气降尘作为一些有害物质的载体,不仅对生态系统造成严重影响,其携带的重金属和多环芳烃等还严重威胁着人体健康,因此大气降尘的污染问题成为人们关注的焦点。攀枝花市作为一座典型的资源型矿业城市,几十年的矿产开发和工矿业的配套发展导致该市大气污染问题突出。因此,研究攀枝花市大气降尘的污染特征并鉴别其污染源,对改善该市大气环境质量具有重要的实际意义。本文通过采集攀枝花地区90多件大气降尘样品,结合环境地球化学、微量元素地球化学和矿物学等学科的方法和原理,从降尘的粒度、矿物组成、水溶性离子特征、微观形貌特征以及重金属的含量和化学形态特征等方面进行综合研究,在此基础上,进一步对降尘的来源进行鉴别,并得到一些初步的结论和认识。攀枝花大气降尘的粒径主要分布在10-50μm之间,颗粒物较细,分选性较差,大于2μm的颗粒物超过95%,受人为活动影响明显。降尘中颗粒物形态复杂,主要有球状结构、块状结构、层状结构、片状结构、条柱状结构,同时也有一些不规则和规则的矿物集合体;矿物成分主要以石英为主,石膏和长石次之,还有一些碳酸盐矿物和钛矿物等,采矿区和冶炼区的有些样品铁矿物含量较高。降尘水溶性组分偏酸性,其中SO42-的贡献率最大,硫酸盐主要以CaSO4形式存在;NH4+和SO42-主要以(NH4)2SO4和NH4HSO4的方式结合;NOX与SOX的质量比大于1,水溶性离子的污染源主要以固定排放源为主。降尘中As、Cd、Cr、Cu、Pb、V、Zn等元素含量超过四川土壤背景值几倍甚至几十倍,Zn和Cd的生物可利用态达到78%和87%,对环境和人体危害较大,Cr、Ni、Cu、As等元素的残渣态含量较高,相对较稳定,其中V、Cd、Zn的污染最为严重;炳草岗、瓜子坪和攀钢区的重金属含量最高,西郊区和仁和区含量最低;降尘的平均粒径与重金属的总含量总体上呈负相关。工业活动、矿山开采、燃煤和交通污染等是影响攀枝花大气的主要因素。
[Abstract]:As a carrier of some harmful substances, atmospheric dust not only has a serious impact on the ecosystem, but also carries heavy metals and polycyclic aromatic hydrocarbons (PAHs), which seriously threaten human health. Therefore, the pollution of atmospheric dust has become the focus of attention. Panzhihua as a typical resource-based mining city, decades of mineral development and industrial and mining industry development led to the city's air pollution problems. Therefore, it is of great practical significance to study the pollution characteristics of atmospheric dust fall and identify the pollution sources in Panzhihua city to improve the atmospheric environmental quality of Panzhihua city. Through collecting more than 90 samples of atmospheric dust in Panzhihua area, combining the methods and principles of environmental geochemistry, trace element geochemistry and mineralogy, the paper analyzes the particle size, mineral composition and water-soluble ion characteristics of dust fall. On the basis of a comprehensive study on the microscopic morphology, the content and chemical speciation of heavy metals, the sources of dust fall were further identified, and some preliminary conclusions and understandings were obtained. The particle size of Panzhihua atmospheric dust was mainly between 10-50 渭 m. The particles were fine and poor in sorting. The size of the particles larger than 2 渭 m was more than 95%, which was obviously affected by human activities. The particles in the dust fall have complex morphology, including spherical structure, block structure, stratiform structure, lamellar structure, stripe columnar structure, and some irregular and regular mineral aggregates, which are mainly composed of quartz. Gypsum and feldspar followed by carbonate minerals and titanium minerals. Some samples in mining and smelting areas have higher iron ore content. The water-soluble components of dust fall are slightly acidic, among which so _ 4 _ 2- contributes the most, and sulphate mainly exists in the form of CaSO4 and so _ 42-, the mass ratio of no _ x to SOX is greater than 1, and the main source of water soluble ions is fixed emission source, which is mainly composed of NH _ 4 and so _ 4 ~ (2-) in the form of NH _ (4) O _ (2) so _ (4) and so _ (4) _ (2-). In dust fall, the contents of trace elements such as aspergite, cdcdcu, cu, Pb, VN and Zn are several times or even tens times higher than those of soil background value in Sichuan province. The bioavailable forms of Zn and CD reach 78% and 87% respectively, and the residual state content of elements such as Crnn, NiNiCU, as, and so on, which are harmful to the environment and human body, is relatively high and relatively stable. The content of heavy metals in Bingcaogang, Guiziping and Panzhihua Iron and Steel area was the highest, and the content of heavy metal in the western suburb and Renhe region was the lowest, and the average particle size of dust was negatively correlated with the total content of heavy metals. Industrial activities, mining, coal combustion and traffic pollution are the main factors affecting the atmosphere of Panzhihua.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X51;X142

【参考文献】