Elemental mercury (Hg0) emission, hazards, and control: A brief review
Haipeng Teng, Adnan Raza Altaf
Abstract
Coal is a widely distributed fossil energy that accounts for 30% of the world's primary energy consumption. However, various toxic pollutants (CO2, SO2, NOx, Hg, H2S, HCl, HCN, etc.) are discharged into the atmosphere during the coal combustion process. Among these poisonous pollutants, mercury (Hg) caused severe harm to the environment and human health. Mercury is a highly volatile metal, capable of spreading over thousands of kilometres, hence becoming a global pollutant, posing a great threat to human life and ecological safety. Coal–fired power plants are a significant source of elemental mercury (Hg0) emission to the atmosphere, the leading cause of mercury hazards in the environment. Thus, controlling the Hg0 emission from coal–fired power plants is crucial. Various advanced techniques have been developed and provided many reasonable solutions; most of them are associated with high operating costs or caused secondary pollutions. The sorbent injection technique is a promising choice with significant economic and environmental benefits for efficiently removing gaseous mercury. This paper briefly analyses the sources and associated health risks of elemental mercury coupled with existing research gaps in the gas purification sector and provide technical assistance to address these gaps.