New Models Used to Determine the Dioxins Total Amount and Toxicity (TEQ) in Atmospheric Emissions from Thermal Processes

Emission Characteristics of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans (PCDD/DFs) in Commercial Bio-SRF and SRF Incineration Plants

Incineration plants using solid refused fuel (SRF) should control their air pollution materials to minimize environmental impact. This study evaluated the emission of polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/DFs) congener patterns in seven commercial incineration plants in Korea using SRF and biomass SRF (bio-SRF). We examined the reduction rate differences of PCDD/DFs, depending on the air pollutant control device. All seven incineration plants sufficiently managed their dioxin emissions. However, both SRF and bio-SRF incineration plants showed active chlorination reactions and resulted in a large amount of highly chlorinated dioxins. The average dioxin concentration was 0.02 ng international toxic equivalency quantity (I-TEQ)/Sm3. Ratios of 1,2,3,4,6,7,8-HpCDF and 1,2,3,7,8-PeCDF were high in the waste heat boilers of both SRF and bio-SRF incineration plants. The octachlorinated dibenzofuran (OCDF) ratio was only high in the SRF incineration plants. Octachlorodibenzo-p-dioxin (OCDD) and OCDF exhibited high dioxin ratios. SRF incineration plants had a low ratio of OCDF to 1,2,3,4,6,7,8-HpCDF. In addition, the reduction rate of PCDD/DFs was substantially high after treatment with the air pollutant control device.

Dioxins and furans toxicity during the photocatalytic remediation of emerging pollutants. Triclosan as case study

The benefits of wastewater remediation technologies are offset in those cases where, as a result of operating conditions, harmful compounds are formed in the degradation routes of the original organic pollutants. This may be the case for the application of some advanced oxidation processes to wastewater containing precursors of dioxins and furans, as previously reported in the application of electrochemical and Fenton oxidation to degrade Triclosan and 2-chlorophenol. This work reports for the first time a detailed kinetic analysis of the formation of dioxins and furans during the photocatalytic treatment of aqueous samples containing 5-Chloro-2-[2,4-dichlorophenoxy] phenol, commercially known as Triclosan. After analysis of the PCDD/Fs concentration, the toxicity of the samples has been determined in terms of toxic equivalents (TEQ). TEQ values have been calculated, first with the group of 17 congeners with higher toxicity. Finally, a multivariable analysis and linear regression have been applied to reduce the significant number of congeners and optimize the analytical effort.