SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2019, Vol. 27 ›› Issue (7): 1708-1715.DOI: 10.1016/j.cjche.2018.10.015

• Energy, Resources and Environmental Technology • 上一篇    下一篇

Degradation of PCDD/Fs in MSWI fly ash using a microwave-assisted hydrothermal process

Qili Qiu1, Xuguang Jiang1, Guojun Lü1, Zhiliang Chen1, Shengyong Lu1, Mingjiang Ni1, Jianhua Yan1, Xiaobing Deng2   

  1. 1 State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China;
    2 Hangzhou Lijia Environmental Services Co., Ltd., Hangzhou 311101, China
  • 收稿日期:2018-08-15 出版日期:2019-07-28 发布日期:2019-10-14
  • 通讯作者: Xuguang Jiang

Degradation of PCDD/Fs in MSWI fly ash using a microwave-assisted hydrothermal process

Qili Qiu1, Xuguang Jiang1, Guojun Lü1, Zhiliang Chen1, Shengyong Lu1, Mingjiang Ni1, Jianhua Yan1, Xiaobing Deng2   

  1. 1 State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China;
    2 Hangzhou Lijia Environmental Services Co., Ltd., Hangzhou 311101, China
  • Received:2018-08-15 Online:2019-07-28 Published:2019-10-14
  • Contact: Xuguang Jiang

摘要: In this work, microwave treatment was introduced to a hydrothermal treatment process to degrade PCDD/Fs (Polychlorinated dibenzo-p-dioxins and dibenzofurans) in municipal solid waste incineration (MSWI) fly ash. Three process additives (NaOH, Na2HPO4, H2O), temperatures (150℃, 185℃, 220℃) and reaction times (1 h, 2 h, 3 h) were investigated to identify their effect on the disposal of fly ash samples through orthogonal experiments. High-resolution gas chromatography-mass spectrometry (HRGC/MS) was applied to determine the PCDD/F concentrations in MSWI fly ash. The experimental results revealed that 83.7% of total PCDD/Fs was degraded. Reaction temperature was the most important factor for the degradation of the total PCDD/Fs. Both direct destruction and chlorination reactions (the chlorination degree of PCDFs increased) took part in the degradation of PCDD/Fs in fly ash, which was a new discovery. Several PCDD/F indexes determined by the concentration of indicative congeners were found to quantitatively characterize the dioxin toxicity of the fly ash. Furthermore, heavy metals in the fly ash sample were solidified using microwave-assisted hydrothermal treatment, which provided an experimental basis for the simultaneous disposal of dioxins and heavy metals. Thus, the microwave-assisted hydrothermal process should be considered for the future disposal of MSWI fly ash.

关键词: Dioxins, Degradation, MSWI fly ash, Hydrothermal treatment, Microwave

Abstract: In this work, microwave treatment was introduced to a hydrothermal treatment process to degrade PCDD/Fs (Polychlorinated dibenzo-p-dioxins and dibenzofurans) in municipal solid waste incineration (MSWI) fly ash. Three process additives (NaOH, Na2HPO4, H2O), temperatures (150℃, 185℃, 220℃) and reaction times (1 h, 2 h, 3 h) were investigated to identify their effect on the disposal of fly ash samples through orthogonal experiments. High-resolution gas chromatography-mass spectrometry (HRGC/MS) was applied to determine the PCDD/F concentrations in MSWI fly ash. The experimental results revealed that 83.7% of total PCDD/Fs was degraded. Reaction temperature was the most important factor for the degradation of the total PCDD/Fs. Both direct destruction and chlorination reactions (the chlorination degree of PCDFs increased) took part in the degradation of PCDD/Fs in fly ash, which was a new discovery. Several PCDD/F indexes determined by the concentration of indicative congeners were found to quantitatively characterize the dioxin toxicity of the fly ash. Furthermore, heavy metals in the fly ash sample were solidified using microwave-assisted hydrothermal treatment, which provided an experimental basis for the simultaneous disposal of dioxins and heavy metals. Thus, the microwave-assisted hydrothermal process should be considered for the future disposal of MSWI fly ash.

Key words: Dioxins, Degradation, MSWI fly ash, Hydrothermal treatment, Microwave