Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
581025 | Journal of Hazardous Materials | 2010 | 8 Pages |
Abstract
Removal of Cu, Pb, and Zn by the action of the two biodegradable chelating agents [S,S]-ethylenediaminedisuccinic acid (EDDS) and methylglycinediacetic acid (MGDA), as well as citric acid, was tested. Three soil samples, which had previously been treated by conventional soil washing (water), were utilized in the leaching tests. Experiments were performed in batches (0.3Â kg-scale) and with a WTC-mixer system (Water Treatment Construction, 10Â kg-scale). EDDS and MGDA were most often equally efficient in removing Cu, Pb, and Zn after 10-60Â min. Nonetheless, after 10Â d, there were occasionally significant differences in extraction efficiencies. Extraction with citric acid was generally less efficient, however equal for Zn (mainly) after 10Â d. Metal removal was similar in batch and WTC-mixer systems, which indicates that a dynamic mixer system could be used in full-scale. Use of biodegradable amino polycarboxylic acids for metal removal, as a second step after soil washing, would release most remaining metals (Cu, Pb and Zn) from the present soils, however only after long leaching time. Thus, a full-scale procedure, based on enhanced metal leaching by amino polycarboxylic acids from soil of the present kind, would require a pre-leaching step lasting several days in order to be efficient.
Keywords
Related Topics
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Chemical Health and Safety
Authors
Zandra Arwidsson, Kristin Elgh-Dalgren, Thomas von Kronhelm, Ragnar Sjöberg, Bert Allard, Patrick van Hees,