摘要
废弃物焚烧过程是环境中二噁英的重要来源,飞灰在焚烧炉后燃区低温段从头合成的二噁英是焚烧炉二噁英 排放的重要组成部分。采用高分辨气相色谱和低分辨质谱联用(HRGC/LRMS)的二噁英检测方法,研究了340℃时氧、碳、催化剂3个重要因素对飞灰中二噁英从头合成的影响。试验结果表明:焚烧炉飞灰在微氧气流中仍能生成二噁英,10％含氧气流时二噁英生成速率为17.1ng/(g.min);焚烧炉飞灰中残碳含量的增加,有利于二噁英的生成;活性炭粉末在CuCl_2催化作用下的二噁英生成速率为31.1ng/(g(AC)·min),是飞灰中残碳从头合成二噁英速率的2～6倍不等;Cu^(2+)催化条件下的二噁英生成速率大于6μg/(g(AC)·mol(催化剂)·min),分别是Cu^+时的1.4倍,Fe^(3+)时的2.7倍。对氧、碳、催化剂等参数的控制可以减少焚烧炉飞灰在后燃区的二噁英生成量,减轻废弃物焚烧炉对环境造成的压力。
Waste incineration processes are important sources of highly toxic PCDD/Fs in environment. De novo synthesis in the low temperature post-combustion zone plays an important role in PCDD/Fs emission during waste incineration. High Resolution Chromatography/Low Resolution Mass Spectrometer technology is used for investigating the effects of oxygen, residue carbon and catalyst on PCDD/Fs formation via de novo synthesis in MSW fly ash at 340℃. The experimental results show that, PCDD/Fs could form in very low oxygen content gas flow; the formation rate 17.1ng/(g·min) is achieved in 10% oxygen content gas flow. It seams that the more residue carbon content in fly ash, the more PCDD/Fs formation will result. The PCDD/Fs formation rate for powder activated carbon with CuCl2 catalyzing is 31.1ng/(g·min), which is about 2-6 times of that for fly ash; The formation rate for Cu2+ catalyzing is over 6μg/(g (AC)·mol (Catalyst)·min), which is 1.4 times of that for Cu+ catalyzing and 2.7 times of that for Fe3+. Results suggest that the controlling of oxygen, residue carbon contents and catalysts will reduce the PCDD/Fs formation in post-combustion zone of waste incinerators and finally will benefit to environment.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2003年第11期178-183,共6页
Proceedings of the CSEE
基金
国家重点自然科学基金(N59836210)
国家重点基础研究发展规划项目(G1999022211
2001CB409600)
浙江省青年科技人才专项资金(RC99041)~~
