Monitoring the variation of atmospheric mercury at a clean water reservoir in northern Taiwan

• Main Authors: Jui-Chi Wang, 王瑞麒
• Other Authors: 席行正
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/35262422802793399823

碩士 === 國立臺灣大學 === 環境工程學研究所 === 105 === Mercury (Hg), one of the global pollutants, has caused severe impacts globally. Atmospheric Hg, the relative stable form in the atmosphere, was removed easily by the atmospheric mechanism due to the bio-accumulate via the food chain. There are three major atmospheric species, gaseous elemental Hg (GEM), reactive gaseous Hg (RGM), and particulate Hg (PHg). The anthropogenic emission sources and the natural emission sources were two major contributors of atmospheric Hg. Therefore, investigating the behavior of atmospheric Hg at a clean water reservoir might provide more knowledge on the Hg enrichment in the reservoir environment, from which water was used for drinking purpose. Results from atmospheric Hg continuous monitoring system were obtained during the sampling period. A 34,872 data amount of GEM was collected with 2.15 ng/m3 as the mean concentration. For RGM, a 2,888 data amount was collected with 2.06 ng/m3 as the mean concentration. For PHg2.5, a 2,892 data amount of PHg2.5 was also collected with 9.09 ng/m3 as the mean concentration. Comparison of other atmospheric Hg continuous monitoring sites was addressed that the concentrations of the study were considered as local background level. Elevated GEM concentrations at 7:00 am to 12:00 am and those decreased at 0:00 am to 7:00 am were exhibited in the study. Photochemical reactions may play an important role in elevated RGM at noon. The PHg2.5 did not show correlation with atmospheric coefficient. Comparison of the sampling method on GEM and PHg was addressed that 32 sample size of GEM and 33 sample size of PHg were collected in the study. The concentrations of GEM from the manual sampling system range from 1.45 to 3.23 ng/m3, and that of the automated speciation data were range from 1.39 to 2.93 ng/m3. The results of GEM and PHg showed high correlation between automated system and manual system by Pearson’s correlation. The simulation of dry deposition addressed that the yearly dry deposition of RGM and PHg was approximately 2.93 μg/m2. The results in the study were 50% underestimated to that of cloud and aerosol lab, namely 7.01 μg/m2. Due to the lack of adequate parameters, such as land use categories and leaf area index, the underestimated results were shown in the study.