The effects of temperature and oxygen content on the PCDD/PCDFs formation in MSW fly ash

被引：65

作者：

Chang, MB ^{[1
]}

Huang, TF ^{[1
]}

机构：

[1] Natl Cent Univ, Grad Inst Environm Engn, Chungli 32054, Taiwan

来源：

CHEMOSPHERE | 2000年 / 40卷 / 02期

关键词：

dioxin formation; municipal waste incinerators (MWI); temperature; oxygen content;

D O I：

10.1016/S0045-6535(99)00227-1

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

In this study. the effects of the temperature, oxygen content in the gas stream and carbon content in ash particles on PCDD/Fs formation on the fly ash surface were investigated. The optimum temperatures for dioxin formation were found at 350 degrees C for boiler ash, 300 degrees C for cyclone ash and 250 degrees C for ESP ash, respectively. Preliminary results indicate that the optimum temperature will decrease as the particle size decreases. When the Oz concentration is varied between 0% and 100%. the optimum oxygen content for PCDD/Fs formation is found to be at 7.5% for cyclone ash, and the PCDD/PCDF ratio increases with the increase of oxygen content. Dioxin formation is observed even for the gas containing no oxygen passed through the fly ash. Hence, other reacted routes that do not need O-2 for dioxin formation take place on fly ash. The carbon content in fly ash is varied between 0% and 20% in this study, and the results have indicated that the maximum dioxin formation is to be found at 5%. The precursors are not injected into the fly ash or gas stream in all formation experiments, however, dioxin is still formed in fly ash. Consequently, other chlorinated routes besides Deacon reactions may take place on the fly ash surface. (C) 1999 Elsevier Science Ltd. All rights reserved.

引用

页码：159 / 164

页数：6

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