Effects of soil amendments on the bioavailability of heavy metals from zinc mine tailings

Abstract

A study was conducted to test the effects of soil amendments on the bioavailability of heavy metals in a zinc mine tailings containing soil to plants, using the Indian mustard plant (Brassica juncea) as a test organism. Zinc mine tailing containing soil was amended with humus soil (HS) and phosphatic clay (PC). The zinc mine tailing containing soil (ZMTS) was characterized for heavy metals. It was mixed with PC and HS, and four mixtures were prepared. The first mixture contained ZMTS, and served as a control. The second mixture contained ZMTS and PC in the ratio of 1:1 (w/w). The third mixture contained ZMTS and HS in the ratio of 1:1(w/w). The fourth mixture containing ZMTS, PC and HS in the ratio of (2:1:1) (w/w). A slight increase in the bioavailability of Pb, Cu, Zn and Mn was noticed with increase in the incubation time from 14 to 42 days. The bioavailability of Pb, Cu, Zn and Mn from ZMTS alone in Brassica plant was in the range of 94-99% up to 42 days. Addition of PC and HS to the ZMTS soil reduced the bioavailabilities of Pb by (15%), of Cu by (20%), of Zn by (20%) and of Mn by (25%) in the mustard plant. The data showed that PC in the presence of HS had a high affinity for the heavy metals in the order of Pb, Cu, Zn and Mn.

Speciation, Fate and Transport, and Ecological Risks of Cu, Pb, and Zn in Tailings from Huogeqi Copper Mine, Inner Mongolia, China

“…of heavy metals in the tailings which followed the order of Zn > Cu > Pb. There was also a strong correlation between the concentration of metals in the leachate and tailings, which is similar to the findings of other researchers [30,31]. The variation of the Pb concentration in the leachate was relatively small while concentrations of Cu varied sharply, especially under acidic leaching conditions.…”

Accumulation of heavy metals and antioxidant responses in Vicia faba plants grown on monometallic contaminated soil

“…The metal fraction in the soil that interacts with a biological target determines its bioavailability (Chojnacka et al 2005; Mishra et al 2009a). In our experiments, some differences in metal concentration series order in the soil extracts and the upper parts of V. faba plants were found.…”

Phytoextraction of toxic metals: a central role for glutathione

“…A prerequisite for phytoextraction is metal uptake by the roots; therefore, it is essential that metals mobilize into the soil solution (Misra et al . 2009).…”

“…A prerequisite for phytoextraction is metal uptake by the roots; therefore, it is essential that metals mobilize into the soil solution (Misra et al 2009). It is evident that plant availability of metals can artificially be increased by adding synthetic chelating agents (Blaylock et al 1997;Huang et al 1997;Chaturvedi, Seth & Misra 2006Misra et al 2009).…”

“…A prerequisite for phytoextraction is metal uptake by the roots; therefore, it is essential that metals mobilize into the soil solution (Misra et al 2009). It is evident that plant availability of metals can artificially be increased by adding synthetic chelating agents (Blaylock et al 1997;Huang et al 1997;Chaturvedi, Seth & Misra 2006Misra et al 2009). However, these compounds can either be phytotoxic (Vassil et al 1998;Geebelen et al 2002;Quartacci et al 2006) or, at the use of high concentrations, leak into aquifers, which is harmful to the environment (Marques, Rangel & Castro 2009).…”