Chelate-enhanced phytoextraction and phytostabilization of lead-contaminated soils by carrot (Daucus carota)

Abstract

The objective of this study was to study the influence of different ethylenediamine tetraacetate (EDTA), nitrilotriacetic acid (NTA) and oxalic acid (HOx) concentrations on tolerance and lead accumulation capacity of carrot (Daucus carrota). The results indicated that by increasing Pb, NTA and HOx concentrations in the soil, the shoot, taproot and capillary root dry matters increase effectively. In contrary, EDTA caused to reduce capillary roots biomass. EDTA was more effective than NTA and HOx in solubilizing soil Pb. The highest Pb content in shoots (342.2±13.9 mg kg -1 ) and taproots (301±15.5 mg kg -1 ) was occurred in 10 mM EDTA, while it occurs for capillary roots (1620±24.6 mg kg -1 ) in 5 mM HOx, when soil Pb concentration was 800 mg kg -1 . The high obtained phytoextraction and phytostabilization potentials were 1208 (±25.6) and 11.75 (±0.32) g Pb ha -1 yr -1 in 10 mmol EDTA kg -1 soil and no chelate treatments, respectively. It may be concluded that chelates application increases Pb uptake by A c c e p t e d M a n u s c r i p t Downloaded by [New York University] at 05:37 23 June 2015 3 carrot. Consequently, this plant can be introduced as a hyperaccumulator to phytoextract and phytostabilize Pb from contaminated soils.

Nitrilotriacetic acid enhanced lead accumulation in Athyrium wardii (Hook.) Makino by modifying rhizosphere characteristics

“…In chelating agent-assisted phytoremediation process, it's the critical point that chelating agents promote the accumulation of HM in plants (Saifullah et al, 2015;Sarwar et al, 2017;Yu et al, 2020). NTA shows great practicability for assisting Pb accumulation in plants due to its high chelating ability, which has been applied successfully to a variety of plants, such as Festuca arundinacea (Zhao et al, 2013), Daucus carota (Babaeian et al, 2016) and Scirpus triqueter ( Hu et al 2017). In this study, NTA application enhanced Pb accumulation in the roots of A. wardii grown in Pb-contaminated soils, keeping consistent with the previous studies of Zhao et al (2016) and , indicating that it's an effective measure to add NTA for improving Pb uptake in A. wardii.…”

“…In order to enhance Pb accumulation in plant, lots of researches have proved the possibility and practicability of using biodegradable chelators, such as nitrilotriacetic acid (NTA), which shows high e ciency in promoting Pb uptake by Brassica carinata (Quartacci et al, 2007), water spinach (Hseu et al, 2013), Siegesbeckia orientalis L. (Lan et al, 2013), Daucus carota (Babaeian et al, 2016) and Scirpus triqueter (Hu et al, 2017). This strategy makes use of NTA to desorb HM from soil particles into soil solutions, thus enhancing the availability and mobility of HM in soils and improving its uptake by plants (Shahid et al, 2012).…”

Phytoremediation of Heavy Metal Pollution: A Bibliometric and Scientometric Analysis from 1989 to 2018

“…Enhanced HM phytoremediation technology has been a hot topic in this field. These technologies include the use of exogenous substances (e.g., organic additives, inorganic additives, fertilizers, auxin applications, exogenous inoculation of bacteria, and microorganisms) [111,112,113,114]. Recently, more attention has been paid to the effects of bacteria/microorganisms on the uptake of HMs in plants [115,116,117].…”

Effect of HEDTA, CDTA, and EGTA Chelates on Remediation of Pb- and Zn-Polluted Soil Using Sunflower and Canola Plants: A Case Study; Soil Around Bama Pb and Zn Mine

“…The current study was conducted to investigate the effect of HEDTA (hydroxyl ethylene diamine tetra acetic acid), CDTA (trans-1,2-cyclohexylene dinitrilo tetra acetic acid), and EGTA (ethylene glycol-bis (β-aminoethyl ether)-N,N,N',N'-tetra acetic acid) chelate on Pb and Zn removal efficiency in a Pb and Zn contaminated soil near the Bama Pb and Zn Mine located in the Southwest of Isfahan. Treatments (48 treatments in three replication) included the application of 0 (M 0 ), 1.5 (M 1.5 ), 3 (M 3 ), and 4.5 (M 4.5 ) mM/kg soil of HEDTA, CDTA, and EGTA chelates (9) twice (one (T 1 ) or two (T 2 ) weeks before harvesting the plant) (10). The plants used in the current study were sunflower and canola.…”