Accumulation of cadmium, lead and strontium, and a role of calcium oxalate in water hyacinth tolerance
1997; Institute of Experimental Botany of the Czech Academy of Sciences; Volume: 39; Issue: 3 Linguagem: Inglês
10.1023/a
ISSN1573-8264
AutoresA. M. A. Mazen, O. M. O. El Maghraby,
Tópico(s)Constructed Wetlands for Wastewater Treatment
ResumoEichhornia crassipes plants brought from the River Nile were cultured in jars containing river water supplemented with various concentrations of Cd, Pb, and Sr (0 to 100 μg cm-3), added simultaneously. Treatment continued for 20 d during which each cultivation solution was being replaced with fresh one every 3 d. The growth of Eichhornia was drastically retarded at heavy metal concentrations higher than 15 μg cm-3. At concentrations 15 or 25 μg cm-3, the accumulation of Cd and Pb to levels several times higher than those in control plants was found. More than 50 % of the uptaken metals were retained by roots alone. Leaves and leaf petiols received around 30 and 20 % of the accumulated metals, respectively. X-ray microanalysis indicated the presence of the three heavy metals in Ca oxalate crystals. Content of metals in the crystals increased progressively over time of exposure in a way similar to those in whole plant tissues. These results suggest a possible role for Ca oxalate crystalization in toxic heavy metal deposition and thus tolerance by Eichhornia.
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