eesti teaduste
akadeemia kirjastus
SINCE 1952
Proceeding cover
of the estonian academy of sciences
ISSN 1736-7530 (Electronic)
ISSN 1736-6046 (Print)
Impact Factor (2020): 1.045

Total and size fractionated concentrations of metals in combustion ash from forest residues and peat; pp. 247–254

Full article in PDF format | doi: doi: 10.3176/proc.2009.4.06

Risto Pöykiö, Hannu Nurmesniemi, Riitta L. Keiski


Environmental characteristics of the total and size fractionated concentrations of metals in bottom ash and fly ash from a large (246 MW) fluidized-bed boiler incinerating forest residues and peat at a pulp and paper mill complex in Finland were studied. Although the enrichment factors for total metal concentrations in the fly ash varied between 1.3 (potassium and sodium) and 34.5 (sulphur), all metal concentrations in both the bottom ash and fly ash were significantly lower than the current Finnish limit values for maximum allowable metal concentrations for forest fertilizers. Therefore, both the studied ashes are residues with a potential to be utilized as forest fertilizers as such. Only the arsenic concentration of 33.0 mg/kg (d.w.) in the fly ash fraction between 1.0–2.0 mm exceeded the Finnish limit value of 30 mg/kg (d.w.) set for arsenic in the forestry fertilizers. This means that the fly ash fraction of 1.0–2.0 mm is not suitable for a forestry fertilizer alone.


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