空气负离子和氡气的分布特征及其与环境因子相关性研究

发布时间：2018-07-06 07:02

本文选题：空气负离子 + 氡气　；参考：《长安大学》2015年硕士论文

【摘要】：自然环境下,氡气在衰变的过程中能够放射出α、β和γ等射线,这些射线的电离能较高,尤其是α射线,能够促使周围空气发生电离,产生空气离子,而空气负离子又能够提高空气的清洁程度,但氡浓度的增高,会加快人体疾病,特别是肺癌的发生。由此可见,空气负离子和氡作为大气中的两种微量组分,对人体健康有相反的影响。因此,研究这二者的相互关系成为了国内外学者关注的焦点。本研究利用DLY-2G型空气离子测量仪和RAD7型测氡仪对长安大学雁塔校区不同环境的空气负离子和氡浓度进行了测量,测量的同时同步记录周围环境的气象因子(温度、相对湿度以及平均风速),在此基础上,分析了空气负离子及氡浓度的时间和空间分布特征,并探讨了其内在原因,另外,对空气负离子和氡浓度与环境因子之间的相关关系也进行了深入分析,最后对空气负离子和大气氡浓度这二者的相关性进行了初步探究。研究结果表明,空气负离子和氡浓度的时间分布呈现明显的不均匀性。空气负离子的日变化呈现明显的双峰变化,即极大值出现在凌晨04:30和下午14:30左右,分别为530和319cm-3,最小值则出现在8:30左右和17:30左右,分别为357和337 cm-3;而氡浓度的日变化略滞后于负离子的变化,且其变化呈现类似正弦曲线的趋势,最大值在清晨06:30左右达到,而最低值出现在16:30左右,分别为18.7Bq/m3和11.1 Bq/m3,且最大值处的峰较明显,最小值处的变化则较为平缓。空气负离子的季节变化趋势均呈现为夏季最高,秋春季次之,冬季最低,而氡浓度的季节变化则呈现完全相反的趋势,即冬天最高,夏季最低。其次,在空间分布方面,操场PG的空气负离子及氡浓度均大于罗马广场LMS的浓度值,但空气负离子在这两处监测点的浓度值没有显著性差异(p=0.0920.05),而氡气的浓度值则存在显著性差异(p=0.000.05)。以环境科学与工程学院楼顶ROS和罗马广场LMS为研究对象研究空气负离子及氡浓度随高度的变化,结果表明高度增加,空气负离子浓度也随之而升高,但浓度差异不显著(p=0.1120.05),而氡气的浓度值则随高度的增高而减小,且浓度值差异显著(p=0.0230.05)。最后,空气负离子和氡浓度与环境因子相关关系的研究发现,空气负离子浓度与温度T、相对湿度RH呈正相关,而与平均风速V呈负相关,对空气负离子浓度的影响程度依次为相对湿度RH、温度T和平均风速V;大气中氡浓度值则与温度T、平均风速V呈负相关,与相对湿度RH呈正相关,且相对湿度RH对大气氡浓度的影响最大,温度T次之,平均风速V最小。
[Abstract]:In the natural environment, radon can emit 伪, 尾 and 纬 rays during decay, and the ionization energy of these rays is higher, especially alpha rays, which can cause the surrounding air to ionize and produce air ions. Air anion can improve the cleanliness of air, but the increase of radon concentration will accelerate the occurrence of human diseases, especially lung cancer. It can be seen that air anion and radon, as two trace components in the atmosphere, have opposite effects on human health. Therefore, the study of the relationship between the two has become the focus of domestic and foreign scholars. In this study, using DLY-2G air ion measuring instrument and RAD7 radon measuring instrument, the air negative ion and radon concentration in different environments in the Yantagar campus of Changan University were measured. The meteorological factors (temperature) of the surrounding environment were recorded simultaneously. Based on this, the temporal and spatial distribution characteristics of air negative ion and radon concentration are analyzed, and the internal reasons are discussed. The correlation between air negative ion and radon concentration and environmental factors was also analyzed. Finally, the correlation between air negative ion and atmospheric radon concentration was preliminarily explored. The results show that the time distribution of air anion and radon concentration shows obvious inhomogeneity. The diurnal variation of air anion shows a bimodal change, that is, the maximum appears at 04:30 and 14:30, 530 and 319cm-3, respectively, and the minimum is about 8:30 and 8:30, respectively. The diurnal variation of radon concentration lags behind that of negative ions, and the variation of radon concentration is similar to that of sinusoidal curve. The maximum value of radon concentration reaches about 06:30 in the morning, and the lowest value is about 16:30. It is 18.7Bq / m3 and 11.1 Bq / m3, respectively, and the peak at the maximum is more obvious, and the change at the minimum is more gentle. The seasonal variation trend of air negative ions is the highest in summer, followed by autumn and spring, and the lowest in winter, while the seasonal variation of radon concentration is completely opposite, that is, the highest in winter and the lowest in summer. Secondly, in terms of spatial distribution, the concentration of air negative ions and radon in playground PG is higher than that of LMS in Rome Square. However, there was no significant difference in the concentration of air negative ions between the two monitoring points (p 0.0920.05), but there was a significant difference in the concentration of radon (p 0.000.05). Taking Ros on the roof of the Institute of Environmental Science and Engineering and LMS in Rome Square as the research object, the variation of air negative ion and radon concentration with height is studied. The results show that the height increases and the air negative ion concentration increases. However, there was no significant difference in the concentration of radon (p0. 1120.05), but the radon concentration decreased with the increase of the height, and the concentration difference was significant (p0. 023. 05). Finally, the study of the correlation between air negative ion and radon concentration and environmental factors shows that air negative ion concentration is positively correlated with temperature, relative humidity RH, but negatively correlated with mean wind speed V. The degree of influence on air negative ion concentration is in turn RH, temperature T and mean wind speed V.The radon concentration in the atmosphere is negatively correlated with temperature T and average wind velocity V, and positively correlated with RH. The effect of relative humidity RH on atmospheric radon concentration is the biggest, followed by temperature T and mean wind speed V.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X51

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