Effect of biodegradable chelators on induced phytoextraction of uranium- and cadmium- contaminated soil by Zebrina pendula Schnizl.

This study investigated the effect of ethylenediamine-N,N′-disuccinic acid (EDDS), oxalic acid (OA), and citric acid (CA) on phytoextraction of U- and Cd-contaminated soil by Z. pendula. In this study, the biomass of tested plant inhibited significantly following treatment with the high concentration (7.5 mmol·kg−1) EDDS treatment. Maximum U and Cd concentration in the single plant was observed with the 5 mmol·kg−1 CA and 7.5 mmol·kg−1 EDDS treatment, respectively, whereas OA treatments had the lowest U and Cd uptake. The translocation factors of U and Cd reached the maximum in the 5 mmol·kg−1 EDDS. The maximum bioaccumulation of U and Cd in the single plants was 1032.14 µg and 816.87 µg following treatment with 5 mmol·kg−1 CA treatment, which was 6.60- and 1.72-fold of the control groups, respectively. Furthermore, the resultant rank order for available U and Cd content in the soil was CA > EDDS > OA (U) and EDDS > CA > OA (Cd). These results suggested that CA could greater improve the capacity of phytoextraction using Z. pendula in U- and Cd- contaminated soils.