Investigation of polycyclic aromatic hydrocarbon content in fly ash and bottom ash of biomass incineration plants in relation to the operating temperature and unburned carbon content.
Investigation of polycyclic aromatic hydrocarbon content in fly ash and bottom ash of biomass incineration plants in relation to the operating temperature and unburned carbon content.
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DOI：
10.1016/j.scitotenv.2016.04.059
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发表时间：
2016-09
期刊：
影响因子：
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通讯作者：
Z. Košnář;F. Mercl;I. Perná;P. Tlustoš
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文献类型：
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作者：
Z. Košnář;F. Mercl;I. Perná;P. Tlustoš
目的全球范围内焚烧发电厂中生物质燃料的使用正在增加。由于多环芳烃（PAH）的存在，产生的灰烬可能对环境构成严重威胁，因为某些PAH是强致癌物、致突变剂和致畸剂。本研究的目的是调查植物体和树状体焚烧产生的飞灰和底灰中总 PAH 和单个 PAH 的含量，因为生物质灰中 PAH 含量的数据有限。研究了不同的焚烧操作温度，并考虑了总PAH含量与灰烬中未燃烧碳之间的关系。方法对从不同生物质焚烧厂收集的飞灰和底灰样品中进行PAHs分析。 PAH 测定采用气相色谱法和质谱法进行。建立了灰烬中低、中、高分子量PAHs之间的相关性。使用回归分析来确定多环芳烃含量和未燃烧碳之间的关系，确定为生物质灰烬中的烧失量 (L.O.I.)。 结果和讨论生物质灰烬中的多环芳烃含量从 41.1 ± 1.8 到 53,800.9 ± 13,818.4 ng/g 干重不等。这种变化可以通过锅炉运行条件和生物质燃料成分的差异来解释。灰分中 PAH 的相关系数范围为 0.8025 至 0.9790。设计了回归模型，确定系数在0.908~0.980之间变化。结论灰烬中PAH含量随燃料类型变化较大，工作温度对灰烬中PAH含量影响明显。飞灰中的多环芳烃含量高于底灰。测试灰烬中以低分子量多环芳烃为主。 PAH 含量与 L.O.I 之间的指数关系观察到飞灰的线性和底灰的线性。
PurposeThe use of biomass fuels in incineration power plants is increasing worldwide. The produced ashes may pose a serious threat to the environment due to the presence of polycyclic aromatic hydrocarbons (PAHs), because some PAHs are potent carcinogens, mutagens and teratogens. The objective of this study was to investigate the content of total and individual PAHs in fly and bottom ash derived from incineration of phytomass and dendromass, because the data on PAH content in biomass ashes is limited. Various operating temperatures of incineration were examined and the relationship between total PAH content and unburned carbon in ashes was also considered.MethodsThe analysis of PAHs was carried out in fly and bottom ash samples collected from various biomass incineration plants. PAH determination was performed using gas chromatography coupled with mass spectrometry. The correlations between the low, medium and high molecular weight PAHs and each other in ashes were conducted. The relationship between PAH content and unburned carbon, determined as a loss on ignition (L.O.I.) in biomass ashes, was performed using regression analysis.Results and discussionThe PAH content in biomass ashes varied from 41.1 ± 1.8 to 53,800.9 ± 13,818.4 ng/g dw. This variation may be explained by the differences in boiler operating conditions and biomass fuel composition. The correlation coefficients for PAHs in ash ranged from 0.8025 to 0.9790. The regression models were designed and the coefficients of determination varied from 0.908 to 0.980.ConclusionsThe PAH content in ash varied widely with fuel type and the effect of operating temperature on PAH content in ash was evident. Fly ashes contained higher amounts of PAHs than bottom ashes. The low molecular weight PAHs prevailed in tested ashes. The exponential relationship between the PAH content and L.O.I. for fly ashes and the linear for bottom ashes was observed.