基于高架点源大气中汞演变规律数值模拟研究  

Mercury from High Elevated Point Source:Numerical Simulation of Its Transformation in Atmosphere

作　　者：刘红芳[1] 王海宁[1] 刘成敏[1] 汪光鑫[1] 

机构地区：[1]江西理工大学资源与环境工程学院,江西赣州341000

出　　处：《环境科学与技术》2014年第9期180-184,共5页Environmental Science & Technology

基　　金：江西省自然科学基金重点项目资助(20133ACB20003)

摘　　要：在分析大气中汞来源的基础上,根据前人研究成果建立了大气中汞的累积量模型,对大气中汞的累积量进行预测。通过合理化简修正高架源扩散模型,采用控制变量法研究了风速、有效源高度、大气稳定度和湿度对Hg扩散的影响,并比较大气稳定度对市区和平原郊区的影响差异。此外,综合分析了上述4个因素对汞在大气中扩散的总体影响。研究结果表明:大气中Hg的扩散是随着有效源的距离增长而逐渐降低;有效源高度不同,其浓度最大值所在的位置就不同,高度越小,其扩散程度越剧烈;湿度越大,Hg的浓度随之增大;大气越稳定,Hg的扩散越稳定,但大气稳定度对市区和平原郊区的影响差异不大,且风速不影响其最大浓度值的所在位置;综合考虑影响大气汞扩散的因素时,风速和有效源高度对大气Hg扩散起协同促进作用;湿度则起抑制作用;大气稳定度与其它几个因素间几乎无影响。On the basis of analyzing the sources of mercury in atmosphere and the results of previous studies, an accumulation model was established to predict the cumulative amount of mercury in atmosphere. Moreover, through properly simplifying and modifying the elevated diffusion model, influential factors, e.g., wind velocity, effective source height, atmospheric stability and humidity, on mercury diffusion were investigated; difference of the effects of atmospheric stability on the diffusion coefficient in urban area and suburban open plain were compared. In addition, the above-mentioned four factors as a whole on mercury diffusion in the atmosphere were analyzed. Results revealed that the diffusion of mercury gradually declined as the distance from the effective pollution source increased; as for the effective source height, the lower the height was, the stronger the diffusion degree would be; as humidity increased, so did the concentration of Hg, and as the atmosphere was stable, so was the mercury diffusion; besides, location of the maximum mercury concentration wouldn＇t be affected by wind velocity. In general, as to the factors that influenced the diffusion of atmospheric mercury, wind velocity and effective source height had synergistic positive effects, humidity could suppress the influences on the diffusion caused by other factors; and atmospheric stability hardly had influences on other factors.

关 键 词：累积量 高架点源模型 演变规律 数值模拟 

分 类 号：X824[环境科学与工程—环境工程]