Induced-phytoextraction of heavy metals from contaminated soil irrigated by industrial wastewater with Marvel of Peru (Mirabilis jalapa L.)

Abstract

The primary objective of this study was to evaluate the effect of ethylene diamine tetraacetic acid (EDTA) and citric acid (CA) on Mirabilis jalapa L. growth and phytoextraction of heavy metals from the multi-metal contaminated soil. The results showed that the application of CA (5 and 8 mmol/kg) and EDTA (5 mmol/kg) increased plant growth, while when the concentration of EDTA was up to 8 mmol/kg, the shoot biomass significantly decreased relative to the control plants (P < 0.05); it suffered 48.1%, 53.1%, 58.9%, and 78.2% reduction, respectively, compared to CK, CA-5, CA-8, and EDTA-5. EDTA was more effective than CA at increasing heavy metal uptake in aerial parts of the plants, the shoot concentrations of Cd, Cu, Pb, and Zn increased by 0.55, 3.08, 3.28, and 1.0-fold in the 8 mmol/kg EDTA-treated soils relative to the treatment of 8 mmol/kg CA. The maximum of Cd, Cu, and Pb phytoextraction and remediation factor (RF) were found with 5 mmol/kg EDTA treatment. For Zn, 8 mmol/kg EDTA was most efficient in increasing Zn accumulation in aboveground of M. jalapa.