Total and size fractionated concentrations of metals in combustion ash from forest residues and peat

Proceedings of the Estonian Academy of Sciences

Riitta L. Keiski¹  Hannu Nurmesniemi¹  Risto Pöykiö¹ 

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关键词: environmental research;    ash;    forest industry;    fluidized bed boiler;    heavy metals;    particle size distribution;    waste;   

DOI  :  10.3176/proc.2009.4.06

学科分类：化学（综合）

来源: Teaduste Akadeemia Kirjastus

【 摘 要 】

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.

【 授权许可】

Unknown