Abstract

The research tested the Brassica juncea ability, to phytoextract and phytostabilize lithium from mine tailings in lieu with vanadium and chromium, sown in a heterogeneous acidic rhizosphere. Five different heterogeneous growth media formulations were prepared from lithium mine tailings, homogenized peat and dewatered municipal biosolids. The Brassica juncea was grown for eighty six days, under homogeneous growing conditions, irrigated bi-daily with organic fertilizer, amended with LiCl, harvested and chemically analyzed. The phytoextraction and phytostabilization data revealed that the Brassica juncea was capable of absorbing more vanadium in its physiological parts rather than lithium and chromium. Likewise the monocotyledonous plant was grown homogeneously on the most favorable growth media, amended with lithium chloride and was able to phytoharness and phytostabilize more lithium rather than chromium per dry weight basis. In botanical efficiency parameters the monocotyledonous plant was ten times more efficient than the Brassica juncea in the bioaccumulation and efficiency removal rates for lithium and twice as much as for chromium. The relative growth rate of the monocotyledonous plant was twice as much as the Brassica juncea. Moreover, it surpassed the monocotyledonous plant in translocation indexes for chromium more than six times and twenty times for lithium. The findings revealed the possibility of a three way symbiosis formed between the hyperaccumulant plant grown in a heterogeneous rhizosphere and coupled with EK system at certain growth periods that will result in an increased electromigration and electrophoresis of heavy metals in the growth media solution.