大气中颗粒态汞的滤膜采样及分析探讨

Discussion on membrane sampling and analysis of particulate mercury in the atmosphere

大气中颗粒态汞在大气汞的循环中具有重要意义,目前尚没有相关分析的国标方法。本研究主要对大气中颗粒态汞的滤膜采样分析及方法进行探讨。经过一系列试验,筛选出Munktell Filter AB产的高纯度石英纤维滤膜作为采样滤膜,通过对滤膜湿法消解上机分析(测汞仪或原子荧光仪)及高温热解法直接分析(测汞仪)的初步研究,证实上述方法及仪器均可用来测定大气中颗粒态汞浓度,可根据具体需要及实际情况采用不同的分析方法。最后用高温热解法对某监测点位取暖期及非取暖期的大气中颗粒态汞的浓度进行测定。其浓度范围在89.1~400.7 pg/m3之间,供暖期浓度明显高于非供暖期,证明燃煤是大气中颗粒态汞的重要来源。

Particulate mercury in the atmosphere was of great significance in the circulation of atmospheric mercury, and there was no national standard method for relevant analysis at present. This study mainly discussed membrane sampling and analysis methods of particulate mercury in the atmosphere. Through a series of experiments, the high-purity quartz fiber membrane produced by Munktell Filter AB was selected as the sampling membrane. Through the preliminary study on the wet digestion of the membrane for analysis(mercury analyzer or atomic fluorescence spectrometer) and the direct analysis by high temperature pyrolysis(mercury analyzer), it is confirmed that the above methods and instruments all could be used to determine the concentration of particulate mercury in the atmosphere, but different analysis methods could be used according to specific needs and actual situation. Finally, the concentrations of particulate mercury in the atmosphere of a monitoring point during heating and non heating periods were determined by high temperature pyrolysis method. The concentration range was 89.1~400.7 pg/m3, and the concentrations in heating period were significantly higher than those in non heating period. It was proved that coal combustion was an important source of particulate mercury in the atmosphere.