被动差分光学吸收光谱法监测污染源排放总量研究

研究了一种测量污染源污染气体(如SO2、NO2)排放总量的光学遥测方法,即采用被动差分光学吸收光谱(DOAS)系统在移动平台(如汽车)上对污染源排放烟羽进行扫描测量,利用被动差分光学吸收光谱处理方法对系统采集的天顶太阳散射光谱进行处理获取柱密度,在结合测量时段的气象(风场)信息后获得污染气体的排放通量,最终得到排放总量。着重描述了获得烟羽垂直柱密度的差分光学吸收光谱方法以及污染气体排放通量的计算方法,并利用车载被动差分光学吸收光谱系统对某一热电厂SO2排放进行了外场测量,实验结果与在线设备的对比表明:这种基于被动差分光学吸收光谱光学遥测方法能够用于污染源排放总量的快速测量。

Monitoring of Total Emission Volume from Pollution Sources Based on Passive Differential Optical Absorption Spectroscopy

An optical remote sensing method for determination of total volume of air pollutants(such as SO2,NO2) emitted from sources is studied,by use of a passive differential optical absorption spectroscopic(DOAS) instrument to scan the plume from pollution source on a mobile platform(such as a car).The column density of air pollutant is retrieved from processing of the scattered sun light spectra in the zenith sky collected by the instrument by means of the spectral analysis method of passive DOAS.Combination with the meteorological(wind field) information during the measurement,the average flux value of air pollutant during the measurement can be estimated then the total emission value can be derived.DOAS method used to obtain the vertical column density the plume and the method used to derive emission flux are described in detail.The passive DOAS instrument was carried by a car to scan the plume from a thermo-power plant in a field measurement.The measurement results and the comparison with the total volume from an on-line monitoring instrument indicate this method based on passive DOAS can be used for rapid remote sensing of the total emission volume from pollution sources.