Li Guo

Publications (3)6.19 Total impact

• Article: A preliminary investigation on emission of polychlorinated dibenzo-p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls from coke plants in China.

  Guorui Liu, Minghui Zheng, Te Ba, Wenbin Liu, Li Guo
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  ABSTRACT: Thermal related processes are widely recognized as the main sources of formation and emission of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). It is well known that, carbonization of coal in coke production involves many thermal reactions at high-temperature. However, there are still no strong evidences to identify coking processes as source of PCDD/Fs and PCBs. In this study, coke production was qualified and quantified for emission of PCDD/Fs and dioxin-like PCBs (dl-PCBs) in some typical coke plants in China. In the preliminary investigation, stack gases from three typical coke plants were collected, and dl-PCBs and 2378-substituted PCDD/Fs were analyzed by isotope dilution HRGC/HRMS technique. The total toxic equivalents of dl-PCBs and PCDD/Fs were in the range of 1.6-1785.4pg WHO-TEQNm(-3). For dl-PCBs, the most abundant congener was CB-118, and the most dominant contributor to total WHO-TEQ of dl-PCBs was CB-126. With regard to PCDD/Fs, four congeners comprised of OCDD, 1234678-HpCDD, 1234678-HpCDF and OCDF were the predominant species in stack gases. Further investigation on the emission of dioxins from coking industry is still in process.
  Chemosphere 03/2009; 75(5):692-5. · 3.21 Impact Factor
• Source

  Available from: jesc.ac.cn

  Article: Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants.

  Li Guo, Bing Zhang, Ke Xiao, Qinghua Zhang, Minghui Zheng
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  ABSTRACT: Concentrations of polychlorinated biphenyls (PCBs) have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight (dw), with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs (World Health Organization-Toxic Equivalents) of the sludge were lower than 1 pg/g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra-CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.
  Journal of Environmental Sciences 02/2009; 21(4):468-73. · 1.66 Impact Factor
• Article: Levels and distributions of polychlorinated naphthalenes in sewage sludge of urban wastewater treatment plants

  Li Guo, Bing Zhang, Ke Xiao, QingHua Zhang, MingHui Zheng
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  ABSTRACT: Over seventy congeners of polychlorinated naphthalenes (PCNs) in sewage sludge of 8 urban wastewater treatment plants (WWTPs) in Beijing were analyzed by isotope dilution, and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) method. The total PCN concentrations determined in the samples range from 1.48 to 28.21 ng/g dw (dry weight) with TEQ concentrations of 0.11–2.45 pg/g dw. These levels were lower than those found in other regions. DiCNs and TrCNs were the most dominant homologues of PCNs. The similar congener profiles in all the samples suggest the similarity in certain sources. Contamination from industrial input might be the most significant source of PCNs in the sludges in this study, and thermal processes such as waste incineration and coal combustion may be another source of the PCNs contamination.
  Chinese Science Bulletin 01/2008; 53(4):508-513. · 1.32 Impact Factor