Efficiency and Effects of Chemical Chelants Leaching on Arsenical Gold Mine Pretreatment by Pteris vittata L. in Arsenical Gold Ore
Using pot experiment, the total arsenic absorbed by Pteris vittata L.from gold roe collected from Guizhou Xingren gold mine was investigated. Arsenic extraction efficiency and effects by five kinds of chelants such as Ethylene diamine tetraacetic acid disodium salt (EDTA-Na2), citric acid (CA), ammonium dihydrogen phosphate (MAP), Sodium bisulfite (NaHSO3) and Sodium bicarbonate (NaHCO3) were assessed. Absorption of As was measured in the fronds and roots of Pteris vittata L.under pot trial condition in which the tested gold ore powder was leached by the above five chelants with the concentrations of 0, 0.05, 0.1 and 0.15 mol•L-1, respectively. The results show that most of the chosen chelants can largely improve the efficiency of arsenic absorption. The leaching efficiency of As in fronds was generally listed in the following order: MAP>EDTA-Na2>CA>NaHCO3>NaHSO3 under the average concentration．With the increase of chelant concentration the As was extracted more and more on MAP and NaHCO3 . The extracting content of As ranged from 5055ug/g to 5974ug/g for EDTA, from3273 ug/g to 4975 ug/g for CA, from 7482 ug/g to 9357 ug/g for MAP and from 3620 ug/g to 5284 ug/g for NaHSO3, from 3401 ug/g to 6378 ug/g for NaHCO3, respectively. The leaching efficiency of As in roots was generally listed in the following order: MAP> NaHCO3>NaHSO3>EDTA-Na2>CA under the average concentration．The extracting content of As ranged from 1862ug/g to 2627ug/g for EDTA, from1494 ug/g to 2347 ug/g for CA, from 2739 ug/g to 3896 ug/g for MAP and from 2064 ug/g to 3373 ug/g for NaHSO3, from 2316 ug/g to 2587 ug/g for NaHCO3, respectively. These results mentioned above show that available As in Guizhou xingren gold mine can be most leached by Pteris vittata L.with the above chelants, especially in MAP treatment. MAP was the best chelants among the four tested chelants, suggesting that it will be useful in chelant-induced phyto-remediation.
Yanguo Shi and Jinlong Zuo
Y. L. Jiang et al., "Efficiency and Effects of Chemical Chelants Leaching on Arsenical Gold Mine Pretreatment by Pteris vittata L. in Arsenical Gold Ore", Advanced Materials Research, Vols. 183-185, pp. 2303-2307, 2011