A safer disposal of hazardous phosphate coating sludge by formation of an amorphous calcium phosphate matrix

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:159

Article

Navarro-Blasco, I.¹  Duran, A.¹  Perez-Nicolas, M.¹  Fernandez, J. M.¹  Sirera, R.¹  Alvarez, J. I.¹ 

[1] Univ Navarra, Dept Chem & Soil Sci, Sch Sci, MIMED Res Grp, Navarra 31008, Spain

关键词: Calcium aluminate cement;    Heavy metals;    Waste management;    Zinc;    Leaching;    Solidification/stabilization;   

DOI  :  10.1016/j.jenvman.2015.05.029

来源: Elsevier

【 摘 要 】

Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50 wt.%. Setting times and compressive strengths were recorded to establish the feasibility of this method to achieve a good handling and a safe landfilling of these samples. Short solidification periods were found and leaching tests showed an excellent retention for toxic metals (Zn, Ni, Cu, Cr and Mn) and for organic matter. Retentions over 99.9% for Zn and Mn were observed even for loadings as high as 50 wt.% of the wastes. The formation of ACP phase of low porosity and high stability accounted for the effective immobilization of the hazardous components of the wastes. (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

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