Mercury (Hg) is a naturally occurring toxic metal that is commonly found in products, such as batteries, paint, and dental amalgam, and in industrial processes such as smelting and chlor-alkali production. Due to its use in these sectors, Hg may be released as emissions into the atmosphere or discharged into aquatic systems; as a result, environmental exposure to Hg is of great concern.
Inhalation and ingestion of mercury are the primary routes of human exposure, and can lead to adverse health impacts, such as severe neurological, immune, reproductive, and cardiovascular effects. As such, effective strategies for removing mercury from both indoor and outdoor air are necessary to reduce public health risks.
One of the most widely applied mercury control strategies is air emission abatement. The efficiencies of these control strategies often rely on the ability to capture and contain the mercury, with the aim of eliminating it from the atmosphere. Mercury capture can occur in a variety of ways, including by adsorption, which involves the trapping of mercury in a material like activated carbon, or by absorption, which is a reversible chemical reaction between mercury and a material that has the ability to bond to it (e.g., a chemical engineered wet scrubber). The abatement strategy selected depends on many factors, such as the type and concentration of mercury present and the cost of implementation.
Another approach to mercury control is through the use of air-cleaning technologies. Activated carbon filters are the most common type of air-cleaning devices employed to remove mercury from indoor or outdoor air. Air passing through the devices is exposed to activated carbon particles, which adsorb and remove the mercury. Other technologies employed to reduce mercury concentrations include oxidizing catalysts, biological devices, and ultraviolet radiation systems.
Finally, there are several ways to remove mercury from the environment. One approach is bioremediation, whereby microbes are used to break down mercury compounds. This technique is commonly used to reduce the levels of mercury in contaminated soil or water. In addition, various chemical and physical processes, such as electrochemical oxidation, chemical reduction, and UV irradiation, can be used to reduce mercury levels in an aquatic environment.
In conclusion, mercury is a toxic metal that can present a considerable health hazard if exposed to large concentrations. To reduce this risk, various technologies are available for capturing, controlling, and removing mercury from both indoor and outdoor air. By safely and cost-effectively removing mercury from the environment, public health risks associated with exposure can be minimized.
