Improved atmospheric mercury simulation using updated gas-particle partition and organic aerosol concentrations  

作　　者：Kaiyun Liu Qingru Wu Shuxiao Wang Xing Chang Yi Tang Long Wang Tonghao Liu Lei Zhang Yu Zhao Qin’geng Wang Jinsheng Chen 

机构地区：[1]State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China [2]State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex,Beijing 100084,China [3]Institute of Atmospheric Environment,Guangdong provincial academy of environmental science,Guangzhou 510045,China [4]China National Environmental Monitoring Centre,Beijing 100012,China [5]State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing,210023,China [6]Center for Excellence in Regional Atmos.Environ.,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China

出　　处：《Journal of Environmental Sciences》2022年第9期106-118,共13页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 21625701 );the Major State Basic Research Development Program of China ( 973 ) (No. 2013CB430001 );the Youth Project of National Natural Science Foundation of China (No. 21607090 );the Shuimu Tsinghua Scholar Program (No. 2021SM017)。

摘　　要：The gaseous or particulate forms of divalent mercury(HgⅡ) significantly impact the spatial distribution of atmospheric mercury concentration and deposition flux(FLX). In the new nested-grid GEOS-Chem model, we try to modify the HgⅡ gas-particle partitioning relationship with synchronous and hourly observations at four sites in China. Observations of gaseous oxidized Hg(GOM), particulate-bound Hg(PBM), and PM 2.5 were used to derive an empirical gas-particle partitioning coefficient as a function of temperature( T) and organic aerosol(OA) concentrations under different relative humidity(RH). Results showed that with increasing RH, the dominant process of HgⅡ gas-particle partitioning changed from physical adsorption to chemical desorption. And the dominant factor of HgⅡ gas-particle partitioning changed from T to OA concentrations. We thus improved the simulated OA concentration field by introducing intermediate-volatility and semi-volatile organic compounds(I/SVOCs) emission inventory into the model framework and refining the volatile distributions of I/SVOCs according to new filed tests in the recent literatures. Finally, normalized mean biases(NMBs) of monthly gaseous element mercury(GEM), GOM, PBM, WFLX were reduced from-33%–29%, 95%–300%, 64%–261%, 117%–122% to-13%–0%,-20%–80%,-31%–50%,-17%–23%. The improved model explains 69%–98% of the observed atmospheric Hg decrease during 2013–2020 and can serve as a useful tool to evaluate the effectiveness of the Minamata Convention on Mercury.

关 键 词：Nested GEOS-Chem model HgⅡgas-particle partitioning Organic aerosol Atmospheric mercury Mercury deposition flux 

分 类 号：X131.1[环境科学与工程—环境科学]