title: 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.
abstract: OBJECTIVE
  The 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.
  
  
  METHODS
  The 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.
  
  
  CONCLUSIONS
  The PAH content in biomass ashes varied from 41.1±1.8 to 53,800.9±13,818.4ng/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.
  
  
  CONCLUSIONS
  The 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.
authors.affiliation: Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 21 Prague 6, Czech Republic. Electronic address: kosnarz@af.czu.cz.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Košnář
authors.affiliation: Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 21 Prague 6, Czech Republic.
authors.forename: Filip
authors.initials: F
authors.lastname: Mercl
authors.affiliation: Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, V Holešovičkách 41, CZ-180 00, Prague 8, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Perná
authors.affiliation: Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 21 Prague 6, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Tlustoš
mesh_terms: D018533:Biomass; D002244:Carbon / Q000032:analysis*; D060729:Coal Ash / Q000032:analysis*; D017745:Incineration; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D011210:Power Plants; D013696:Temperature
chemical_list: D060729:Coal Ash; D011084:Polycyclic Aromatic Hydrocarbons; D002244:Carbon
keywords: Ashes; Biomass combustion; Combustibles; Incineration temperature; PAHs