Assess PCDD/Fs Transfer in The Environmental Medium by a Mass Balance Model

• Main Authors: Chien Tsai Chuang, 莊見財
• Other Authors: Chieh Lin
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/25290884019831896730

碩士 === 國立屏東科技大學 === 環境工程與科學系 === 90 === Incineration is recognized as one of the most efficient processes to treat and dispose the waste stream. An obvious advantage of incineration is the large mass and volume reduction. The oxidation of hydrocarbon contents in the waste stream is a very complex process involving both propagation and chain-branching reactions. The higher the carbon atom number of the hydrocarbon, the more complicated is the process. The major concern regarding air pollutant emissions from waste incineration system is to form some organic products of incomplete combustion (PICs) especially polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs). Some of them are thermally stable and suspected of being mutagenic and carcinogenic to human. Due to the more stringent regulations of the stack emission, it is the more important in providing an understanding of potential environmental and human health exposure pathways about PCDD/Fs. After the PCDD/Fs emission standard of large scale and small to medium scale incinerator were promulgated, the most hazardous air pollutants were switched from the gas phase (i.e. the flue gas) to solid phase (i.e. the ash matrix) in order to meet the most stringent criteria in the world. The aim of this research is to explore whether PCDD/Fs transfer in the environmental medium that takes place mainly through air-to-plant or soil-to-plant. The primary results of this study are summarized as follows: (1) PCDD/Fs in the atmosphere are partitioned into the particulate phase and vapor phase depend on the oriented chlorination (2) The temperature and the carrier gas are the key dominant parameters varied the distribution of the chlorinated compounds. (3) The concentrations of PCDD/Fs can be estimated based on the mass balance model very consistent with the measured level between the air, the soil and the plant samples near the incinerator facility. (4) Although the concentration discrepancy between the rural soil sample and the modeling results, the homologue patterns of PCDD/Fs is similar to each other. (5) The vapor phase PCDD/Fs transformation plays a crucial role in the food chain and the theoretical model will be further applied to understand the human exposure to PCDD/Fs.