Extractability of heavy metals in cyclone ash

Proceedings of the Estonian Academy of Sciences

Lilli Paama¹  Toomas Tenno¹  Hannu Nurmesniemi¹  Risto Pöykiö¹  Hannu Rönkkömäki¹ 

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关键词: environmental research;    air pollution;    ash;    cyclone;    extraction;    heavy metals;    waste;   

DOI  :  10.3176/proc.2008.2.04

学科分类：化学（综合）

来源: Teaduste Akadeemia Kirjastus

【 摘 要 】

Landfill disposal is the only reasonable option for cyclone ash due to its elevated concentrations of the heavy metals Cd (25 mg kg–1; d.w.), Zn (3630 mg kg–1; d.w.), Ba (4260 mg kg–1; d.w.), and Hg (1.7 mg kg–1; d.w.). The distribution of heavy metals (i.e. Cd, Cu, Pb, Cr, Zn, As, V, and Ba) after a three-stage BCR sequential extraction procedure between the exchangeable (CH3COOH), easily reduced (NH2OH–HCl), and oxidizable (H2O2 + CH3COONH4) fractions showed that the highest concentra­tions of most of the heavy metals occurred in the oxidizable fraction. This indicates that a major part of the heavy metals retained in the cyclone ash originating from a small-scale (6 MW) municipal district heating plant incinerating forest residues (i.e. wood waste and bark) are not easily liberated under the conditions normally found in nature.

【 授权许可】

Unknown