The Emission of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans from Steel and Cement-Kiln Plants in Vietnam

Abstract

Stack gas and fly ash samples were collected in two steel plants and three cement kiln plants for the determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). A standard sampling method (U.S EPA method 23) was used following the requirements for isokinetic sampling of stack gas emission. The quantification of PCDD/Fs was done by high resolution gas chromatography, coupled with high resolution mass spectrometry (HRGC/HRMS). The results demonstrated that PCDD/F concentrations in steel plants varied from 0.234 to 0.577 ng/Nm3 on a mass basis, and 0.048 to 0.166 ng/Nm3 on a TEQ basis. In cement kiln plants, the mass concentration varied from 0.280 to 5.32 ng/Nm3, while TEQ concentration varied from 0.033 to 0.837 ng TEQ/Nm3. In general, PCDD/F emissions from steel industry in Vietnam were slightly lower than those reported for European Union, and were comparable to those reported for Taiwan and Korea. A similar trend was observed for the emissions of PCDD/Fs from cement kiln industry in Vietnam. PCDD/F emission factors for steel and cement kiln industries were also estimated to compare with the guidelines of the UNEP for persistent organic pollutants (POPs) inventory.