Chemical properties of rare earth elements in typical medical waste incinerator ashes in China

JOURNAL OF HAZARDOUS MATERIALS

卷:158

Article

Zhao, Lijuan¹  Zhang, Fu-Shen¹  Zhang, Jingxin² 

[1] Chinese Acad Sci, Ecoenvironm Sci Res Ctr, Beijing 100085, Peoples R China

[2] Harbin Environm Monitoring Ctr, Harbin 150016, Peoples R China

关键词: Medical waste;    Incinerator ash;    Rare earth element;    Sequential extraction;    Bioavailability;   

DOI  :  10.1016/j.jhazmat.2008.01.091

来源: Elsevier

【 摘 要 】

Medical waste (Mw) ashes from different types of MW incinerators were examined to detect the characteristics and environmental impact of rare earth elements (REEs). The results showed that total REE contents in the ash samples ranged from 10.2 to 78.9 mg/kg. REEs in bottom ash were apparently higher than those in fly ash. Average REE contents in the ashes followed the sequence of Ce>La>Nd>Y>Gd>Pr>Sm>Dy>Er>Yb>Ho>Eu>Tb>Lu>Tm. Some of the elements, such as Sin, Dy. Ho. Er, Yb in the ash samples were in normal or nearly normal distribution, but Y. La. Ce, Pr, Nd, Eu, Gd, Th. Tm, Lu were not normally distributed. indicating some of the ash samples were enriched with these elements. Crust-normalized REE patterns indicated that two types of the MW ashes were Obviously enriched with Gd and La. Sequential extraction results showed that REEs in the ash mainly presented as residual fraction, while exchangeable and carbonate fractions were relatively low. DTPA- and EDTA-extraction tests indicated that REEs in the MW ashes were generally in low bioavailability. (C) 2008 Elsevier B.V. All rights reserved.

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