连云港滨海大气中水溶性阴离子的研究

【作者】 赵恒强；

【导师】 郑晓玲；

【作者基本信息】 国家海洋局第一海洋研究所 ， 海洋化学， 2008， 硕士

【摘要】 目前,我国沿海工业发展迅速,海洋大气对金属材料的腐蚀造成了巨大经济损失。特别是滨海核电站的大气腐蚀,存在严重的环境和健康隐患。大气中阴离子成分是造成大气腐蚀的重要因素。为了了解海洋大气的腐蚀特性,研究大气阴离子成分在大气中的存在、迁移、扩散和消除过程,对于了解工程材料在海滨大气环境下的耐蚀特性及腐蚀规律,合理选用材料,采取合适防腐措施,控制腐蚀,延长设备及构件使用寿命具有重要意义。本文于2005年6月至2006年5月,在连云港滨海的田湾核电站采集了大气吸收液样品594个,总悬浮颗粒物（TSP）样品300个,湿沉降样品114个,干沉降样品36个。采用离子色谱法测定了样品中的Cl^-、NO₃^-、SO₄^2-等水溶性无机阴离子。本文主要开展如下几个方面工作:第一章对大气中化学组分的国内外研究现状进行了综述,主要论述了大气中水溶性离子、重金属、有机物的研究方法及进展,提出了本论文的研究内容。第二章对本实验所采用的仪器、试剂、实验流程和实验方法进行阐述。第三章考察了大气、TSP、湿沉降、干沉降中3种水溶性无机阴离子及TSP质量浓度的浓度水平和时间分布特征。结果表明:大气、TSP、湿沉降、干沉降中3种主要水溶性阴离子含量有相同的顺序:SO₄^2-含量最高,Cl^-次之,NO₃^-最少。连云港滨海大气中3种阴离子含量有明显的季节变化:大气中Cl^-、SO₄^2-浓度夏季较高、冬季较低,而NO₃^-浓度秋季较高、夏季较低;TSP质量浓度春季较高、夏季较低;TSP中Cl^-浓度在春秋季高、夏冬季低,TSP中NO₃^-、SO₄^2-浓度在冬春季较高、夏秋季较低;湿沉降中NO₃^-、SO₄^2-浓度在冬春季较高、夏秋季较低,湿沉降中Cl^-浓度在秋冬季较高、在春夏季较低;干沉降中Cl^-、SO₄^2-浓度夏季较高、冬季较低,干沉降中NO₃^-浓度春秋季较高、夏冬季较低。对大气、TSP、湿沉降、干沉降中3种主要水溶性阴离子浓度及TSP质量浓度进行了相关分析,结果表明:大气中SO₄^2-分别与Cl^-、NO₃^-呈显著的正相关性,而Cl^-和NO₃^-相关性较低,这说明大气中的SO₄^2-与Cl^-和NO₃^-在不同时期可能有相似的来源,而Cl^-与NO₃^-来源存在较大差别。TSP中Cl^-与NO₃^-呈显著正相关,与SO₄^2-有相关性;TSP中NO₃^-与SO₄^2-呈显著的正相关性;TSP中Cl^-、NO₃^-、SO₄^2-与TSP质量浓度均呈显著正相关性。大气中NO₃^-与TSP中NO₃^-、SO₄^2-有明显正相关性,大气中SO₄^2-与TSP中NO₃^-、SO₄^2-有明显正相关性,这表明大气与TSP中NO₃^-、SO₄^2-可能有相同的来源。大气中Cl^-与TSP质量浓度有明显负相关性,这可能是因为大气中的Cl^-受海洋影响较大,而大气中的颗粒物来源于内陆干旱地区。湿沉降中NO₃^-与SO₄^2-呈显著的正相关性,降雨量与湿沉降中NO₃^-、SO₄^2-浓度呈显著的负相关性,这表明降水中的离子主要来源于大气中气溶胶颗粒和气体的溶解,大的降水量使降水体积增加,降水中酸性离子的浓度相应降低。干沉降中Cl^-、SO₄^2-有正相关性。第四章考察了风向、风速、相对湿度、气温、气压、近海表层水温、浪高、降雨量等气象因素对大气中水溶性阴离子浓度的影响。对气象因素与大气中阴离子浓度进行了相关分析。结果表明:风向、气温、近海表层水温、湿度、气压与大气中阴离子浓度相关性显著。第五章总结了本论文的主要结论。更多还原

【Abstract】 Economic losses caused by corrosion of the industrial facilities and machineries by the salty marine atmosphere has become a major problem in the coastal regions of China in recent years. Of particular concern are the corrosion problems exist in nuclear power plants because of the serious environmental and health implications involved. Atmospheric anions are the ones responsible for most of the corrosion problem in marine air. Thus, to gain better understanding on the physiochemical properties, the transport and the environmental fate of atmospheric anions is important for corrosion control through the selection of proper materials, the development of preventive methods, and the design of effective anti-corrosion technologies.During the study period from June 2005 to May 2006, a total of 594 Atmospheric Absorb Solution（AAS） samples, 300 Total Suspended Particle（TSP） samples, 114 Wet Deposition（WD） samples and 36 Dry Deposition （DD）samples were collected at Tianwan nuclear power plant in the Lianyungang coastal region. The water soluble inorganic anions (Cl^-、NO₃^-、SO₄^2-) in each of these samples were analyzed by Ion Chromatography （IC）. The results and discussions in the thesis is organized into the following five chapters:In Chapter 1, the methods and trends in the research of atmospheric chemical compositions such as water soluble ions, heavy metals and organic compounds are reviewed. The objectives of the study are also described in this part.Chapter 2 discusses the experimental aspects of IC, including instrumentation, reagents usage, operational conditions, the detection mechanism and data processing routines.Chapter 3 presents the concentration levels and seasonal characteristics of three water soluble atmospheric inorganic anions, AAS, TSP, WD and DD, and the quality control practices in these measurements. The results show that the concentrations of the three water soluble inorganic anions in AAS, TSP and WD and DD follow the same trend: SO₄^2- > Cl^- > NO₃^-. The concentrations of these pollutants show notable seasonal variations : the concentrations of Cl^- and SO₄^2- in AAS are higher in summer and lower in winter; the concentration of NO₃^- is higher in autumn and lower in summer; the quality concentration of TSP is higher in spring and lower in summer; the concentration of Cl^- in TSP is higher in spring and autumn; but lower in summer and winter; the concentration of NO₃^- and SO₄^2- are higher in winter and spring but lower in summer and autumn; the concentration of NO₃^- and SO₄^2- in WD are higher in winter and spring but lower in summer and autumn; the concentration of Cl^- is high in autumn and winter but lower in spring and summer; the concentration of Cl^- and SO₄^2- in DD are higher in summer but lower in winter; and the concentration of NO₃^- is higher in spring and autumn but lower in summer and winter.The results of correlation analyses show the existence of good correlations between SO₄^2- and Cl^-, and SO₄^2-and NO₃^- in AAS. However, the correlation coefficient between Cl^- and NO₃^- is lower. This suggests that SO₄^2- may have the same source as Cl^- and NO₃^- during different seasons. However, Cl^- and NO₃^- likely to have different sources. In TSP, there is a good correlation between Cl^- and NO₃^-, and also between NO₃^- and SO₄^2- . There are also good correlations between Cl^-, NO₃^-, SO₄^2- and the mass concentration in TSP. Good correlations exist between both NO₃^- in AAS and both NO₃^- and SO₄^2- in TSP. Good correlations also exist between SO₄^2- in AAS and both NO₃^- and SO₄^2- in TSP. These results illustrate that NO₃^- and SO₄^2- in both AAS and TSP may have the same sources. Negative correlation exist between Cl^- in AAS and mass concentration of TSP. This is mainly because that Cl^- in the atmosphere is affected highly by ocean, however the aerosol mainly comes from droughty region inland. Good correlations exist between NO₃^- and SO₄^2- in WD; negative correlation exist between rainfall and both NO₃^- and SO₄^2- in WD. This indicates that these ions mainly come from the dissolution of aerosols and acidic gases in the atmosphere. During heavy rainfall, the water volume increases, resulting in lower concentrations of acidic anions in WD.Chapter 4 summarizes the effects of meteorological parameters to the concentration of water soluble anions in Lianyungang. The parameters studied include wind direction,wind speed,relative humidity,temperature,air pressure,water temperature surface layer inshore,wave height, and rainfall. Correlation analyses have been made between water soluble anions and each of the above meteorological parameters. Among the parameters studied, wind direction,temperature, water temperature surface layer inshore,humidity and air pressure are the ones affecting the anion concentrations the most.Major conclusions are summarized in chapter 5.更多还原