Introduction

Phytoremediation offers an alternative for removal of contaminants that are soil-present. Chrysopogon zizanioides (Vetiver) is a phytoremediation plant that has provided favorable results in the removal of metals. However, trace elements of metal are retained in the soil without them being bioavailable to the species, knowing that the utilization of chelating agents such as acids that are utilized in this research, which in organic acids stand out, improve phytoremediation processes making retained-in-soil-and-plants metals bioavailable. The objective of this research was to evaluate the effect of organic acids regarding the bioavailability of heavy metals in Vetiver, a soil exposed to leachate of urban solid waste from Sanitary Landfill Environmental Promoting Company S.A.B de C.V

Method

C. zizanioides propagated from cuttings that were acclimatized before being placed in experimental units which contained the soil from the landfill. These cuttings were exposed to leachate for 40 days, to which were added organic acid solutions (citric acid and tartaric acid at 10 mM and 15 mM). Soil was characterized, pH was measured, Organic Matter, Texture based on NOM-021-SEMARNAT-2000 and Aguilera and Domínguez (1982). The analysis of the metals present in the root, leaf and soil samples was carried out by means of Optical Emission Spectrometry by Inductive Coupling Plasma (ICP-OES).

Results

An increase in the pH and organic matter of the soil was observed in the treatments in which organic acid solutions had been added, the treatment with 10 mM citric acid mobilized in the soil the greater amount of Lead, Thallium and Vanadium, in the same way T2 with 10 mM citric acid accumulated the most of the metals under study in the Vetiver plants, achieving a greater accumulation of Thallium and Vanadium in the leaves of the plant.

Discussion or Conclusion

The presence of organic acids in the soil where Vetiver grows had an effect with significant differences on the physicochemical properties of the soil, increasing the levels of pH and organic matter, thus favoring the absorption of metals towards the Vetiver plant. The T1 that corresponds to the treatment with citric acid 10 mM, was the one that obtained greater effectiveness during the mobilization of metals (Lead, Thallium and Vanadium). We identified toxic elements such as Vanadium present in the soil and the plant, it is the first time that it is mentioned that this species absorbs it and accumulates it at high concentrations of Vanadium in the roots, thus constituting a successful phytostabilization process in soils contaminated by this element.