Evaluation of PCDD/Fs Congener Partitioning between Vapor/Solid Phases effect of water onto the Fly Ashes

• Main Authors: Lichi-Chiu, 邱莉祺
• Other Authors: Dr. Chieh Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/82466898296396241836

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 97 === In full-scale MSW incinerator operation, the incoming refuse contains a certain content of moisture, which may ultimately affect the formation or destruction of PCDD/PCDF. The effect of water vapor on catalyzed de novo formation of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) was investigated through experiments conducted on a fixed-bed apparatus. Experiments with PCDD/Fs adsorption by activated carbon were performed using a bench-scale packed bed reactor at the practical temperature range in the air pollution control devices. Water vaper was added into the fly ash matrix to test the effect of PCDD/Fs formation and destruction. In the 25% of water vaper addition case, the PCDD/Fs concentration onto the fly ash matrix creased from 206.3 ng/min to 174.12 ng/min based on the same reaction time scale. However, the homologue profiles and the isomer distribution were changed less PCDD in the flu gas matrix of the PCDD creased from 42.84 ng/min to1.65 ng/min based. showed that in the presence of water considerably less PCDD in the flu gas matrix was detected. On the moisture, the homologue patterns shift to lower chlorinated homologues when water is added into the reacting gas phase. In the 8% and 25%of water vaper addition case, the PCDD/Fs concentration onto the fly ash matrix creased from133.66 ng/min to 174.12 ng/min based on the same reaction time scale. However, the homologue profiles and the isomer distribution were changed more in the ash matrix of the PCDD increased from116.11 ng/min to160.00 ng/min based. The moisture is higher, the homologue patterns shift to more chlorinated homologues when water is added into the OCDD in the ash. In the 3% activated carbon and 8% water vaper addition case, the PCDD/Fs concentration onto the fly ash matrix increased from245.26 ng/min to65.24 ng/min based on the same reaction time scale. However, the homologue profiles and the isomer distribution were changed in the ash and flu gas stream. The ratio of PCDD/PCDF creased from 29.95 to 2.88. On the moisture, the observations suggest that the activated carbon plays a critical role in PCDD/Fs adsorption under the experimental conditions. To showe that in the presence of water considerably less PCDD in the flu gas matrix was detected. In the 0.1% Naphthalene activated carbon and 8% water vaper addition case, the PCDD/Fs concentration onto the fly ash matrix increased from157.21 ng/min to334.95 ng/min based on the same reaction time scale. However, the homologue profiles and the isomer distribution were changed more in the flu gas matrix of the PCDD from 5.08 ng/min to176.71 ng/min based increased 33 times ,the result different from adding Naphthalene experiment appearing and the fly ash, respectively. The dominant precursor of PCDD/Fs formation more in the flu gas matrix of the PCDD, was PAHs based on this study. The homologue patterns shift to more chlorinated homologues when water is added into the HpCDD in the flu gas.