The 1990 Clean Air Act Amendments (CAAA) address 189 hazardous air pollutants (HAPs) considered harmful to human health and the environment and found that the Mercury and its compounds are one of the highest priority pollutants to study. CAAA requested that the United States Environmental Protection Agency (EPA) conduct a study on mercury emissions, including those from electric utility steam generating units. In 1997, the EPA released the Mercury Study Report to Congress, which analyzed mercury emissions from power plants and studied control technologies. In 1998, the EPA released a study on toxic substances in utility air, which also showed mercury as a high priority pollutant due to its potential for multi-route exposure and its ability to bioaccumulate and persist in the environment as methylmercury. [1, 2]Control of mercury in flue gases is highly dependent on speciation. Oxidized mercury is removed relatively easily by particulate control equipment as well as wet scrubbers used to control sulfur dioxide. However, elemental mercury is very volatile and has very low solubility in water, allowing it to escape through most pollution control equipment. The objective of this project is to understand the importance and contribution of carbon constituents in the gas phase in mercury oxidation reactions. The project involves experimental efforts. The objective is to determine the important experimental parameters in homogeneous oxidation reactions; effect of each of these parameters on the oxidation of mercury for different concentrations and temperatures. The objective of this project was to test the performance of bromine and chlorine (Cl2) on the homogeneous oxidation of mercury in the presence of common flue gas components such as nitric oxide...... middle of paper ...... constituents or itself before being able to oxidize the mercury at the required temperature. A fundamental understanding of mercury flue gas chemistry is necessary to develop effective mercury control technologies. Since the reactions of atomic and molecular chlorine with other flue gas constituents determine the concentration of reactive chlorine species remaining in the cooled gas, the effects of specific gaseous constituents on chlorine-mercury have been studied in a manner in-depth. Experimental data indicate a negative effect of mercury chlorination by SO2 and NO in the presence of H2O [13]. Recent experimental data from EERC indicate that bromine species have high potential in mercury control applications [12]. In the proposed study, emphasis is placed on the homogeneous reactions of mercury in flue gases with Br2 and Cl2 in the presence of other flue gas constituents..