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

Abstract

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.

Extraction of Cobalt and Cadmium in Municipal Dump Sites around Zaria, Kaduna State Using EDTA and Citrate as Complexing Agents

“…Hence the removal of metals from the soil is a function of time and concentration (Jean et al 2007;Gzar et al, 2014). Chelating agents; EDTA shows a higher extraction yield than Citrate for both cobalt and cadmium in this present study, this is in agreement with other works that reports EDTA as a more attractive complexing agent than Citrate (Chao et al, 1998;Jerome et al, 2007;Masakazu et al, 2008;Wuana et al, 2010;Chen et al, 2019;Cheng et al;. This is due to its ability to form strong metal-ligand complexes which increases its chelating effect.…”

“…The merits of chelating agent include their ability to complex metal ions, removing target metal ions from the environment, decrease/stoppage of metal precipitation and favouring ion crossing through biological machine (Nurchi et al, 2020). In addition, the chelating agents cause only minor impact on the physical and chemical properties of the solid matrix as compared to acids (Lee and Marshall, 2002 ;Chen et al, 2019).…”

COMPARATIVE EXTRACTION OF Mn AND Pb USING EDTA AND CITRATE TO ASSESS THEIR MOBILITY FROM TWO DUMPSITES IN ZARIA METROPOLIS

“…Extraction yield for the complexing agents used shows EDTA having a higher yield than Citrate for all the metals under study, this is in agreement with other works that reports EDTA as a more stronger complexing agent than Citrate (Jerome etal., 2007;Masakazu et al, 2008;Wuana et al, 2010;Wei et al, 2011;Chen et al, 2019;Cheng et al;. This observation is explicable by the fact that chelate effect is more in EDTA; this effect is found to confer extra stability on chelates and largely originates from an increase in entropy resulting from an increase in the number of free molecules liberated as the chelate is formed.…”

“…The advantages of chelating agent include high efficiency of metal extraction, high thermodynamic stabilities of the metal complexes, and low absorption of the chelating agents to a catalyst (Jerome et al, 2007). In addition, the chelating agents cause only minor impact on the physical and chemical properties of the solid matrix as compared to acids (Lee and Marshall, 2002 ;Chen et al, 2019). Several types of extractants can be used to extract heavy metals and metalloids from contaminated soil for soil washing technology.…”

Chelating Agents in Assisting Phytoremediation of Uranium-Contaminated Soils: A Review

“…As summarized from Table 3, the application rates of chelating agents alone in assisting phytoremediation of U-contaminated soils ranged from 0.5 to 25 mmol/kg. In addition, previous studies reported that chelating agents (e.g., EDDS, EDTA, and DIPA) reduced plant biomass and even caused plant mortality at application rates greater than 5-7.5 mmol/kg [27,28,160,161]. The impact of chelating agents on plant growth is also related to the types of chelating agent and plant.…”