Heavy metal speciation and phytotoxic effects of three representative sewage sludges for agricultural uses
The environmental impact of sewage sludges depends on the availability and phytotoxicity of their heavy metal. The influence of representative sludges (dewatered anaerobic, pelletization, and composted sludge) on the availability of heavy metals, and their effects on seed germination were compared. The total heavy metal concentrations were below the maximum permitted for land-applied waste and the differences among them were small. The DTPA-extracted metal concentrations were rather different. The sequential extraction of the compost showed a slight increase in Cd and Cu availability, and a decrease in the availability of Fe, Mn, Ni and Zn. Pelletization increased the availability of Ni and slightly reduced that of Cr. The dewatering sludge led to greater availability of Cr and Mn but reduced the concentration of Cd. The three different sludges also affected seed germination and root elongation in different ways. The most serious adverse effects were caused by the dewatered sludge extract. © 2005 Elsevier Ltd. All rights reserved.
| Main Authors: | , , |
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| Format: | journal article biblioteca |
| Language: | English |
| Published: |
Elsevier
2006
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| Subjects: | Sewage sludge, Metals-DTPA extraction procedure, Metal speciation, Germination test, Root elongation, |
| Online Access: | http://hdl.handle.net/20.500.12792/5559 http://hdl.handle.net/10261/295059 |
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