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Advances in Environmental Research Volume 5, Number 1, March 2016 , pages 19-35 DOI: https://doi.org/10.12989/aer.2016.5.1.019 |
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Single and mixed chelants-assisted phytoextraction of heavy metals in municipal waste dump soil by castor |
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Raymond A. Wuana, Ishaq S. Eneji and Julius U. Naku
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| Abstract | ||
| The phytoextraction of some toxic heavy metals from municipal waste dump soil by castor plant (Ricinus communis) was tested under natural and single or mixed chelant-assisted scenarios in pot microcosms. A sandy loam with total metal contents (mg/kg): Cd (84.5), Cu (114.5), Ni (70.3), Pb (57.8), and Zn (117.5), was sampled from an active dumpsite in Calabar, Nigeria and used for the study. Castor (small seed variety) was grown under natural phytoextraction or single/binary chelant (citric acid, oxalic acid, and EDTA) applications (5-20 mmol/kg soil) for 63 days. Castor exhibited no visual phytotoxic symptoms with typically sigmoid growth profiles at the applied chelant doses. Growth rates, however, decelerated with increase in chelant dose. Post-harvest biomass yields were higher under chelant application than for natural phytoextraction. Both root and shoot metal concentrations (mg/kg) increased quasilinearly and significantly (p | ||
| Key Words | ||
| waste dump soil; heavy metals; Ricinus communis; phytoextraction; mixed chelants | ||
| Address | ||
| Department of Chemistry and Centre for Agrochemical Technology, Federal University of Agriculture, Makurdi 970001, Nigeria | ||
