Chelate-assisted phytoextraction of cadmium from a mine soil by negatively charged sunflower

Abstract

The effects of some chelating agents and electricity on cadmium phytoextraction from a mine soil were examined in pot culture of sunflower to achieve more remediation efficiency. At the beginning of the flowering stage, ethylene-diamine-tetra-acetic acid (EDTA) as a chemical chelator, cow manure extract (CME) and poultry manure extract (PME) as organic chelators were applied (2 g kg -1 soil) during irrigation. Seven days later, Helianthus annuus was negatively charged by inserting a stainless steel needle in the lowest part of the stem with 10 and 30 V direct current electricity for 1 h each day for 14 days. Afterward, concentration of cadmium in roots and shoots, cadmium translocation factor (TF), cadmium uptake index (UI) and soil available (diethylene-triaminepenta-acetic acid extractable) cadmium were measured. Results indicated that EDTA reduced roots dry weight while none of the roots and shoots was affected by other chelating agents and by electrical treatment as well. Highest concentration of cadmium in shoots was measured in 10 V-control with no significant differences with 30 V-PME and 30 V-EDTA. Utilization of chelating agents did not increase the cadmium TF and cadmium UI while highest values for cadmium TF and cadmium UI were observed in 10 and 30 V treatments, respectively. Available cadmium in the soil near root system treated with 10 and 30 V was relatively lower compared with the soil far from root system. Results of this experiment indicated that charging the plant with direct current electricity ameliorated the efficiency of cadmium phytoremediation.

Evaluation of the phytoremediation potential of three plant species for azoxystrobin-contaminated soil

“…There have been several studies focused on the phytoremediation of pesticides (Romeh and Mohammed 2013;Romeh 2014, Zhang et al 2014, Ibáñez et al 2014. Sunflower (Helianthus annuus L.) is a relatively high-biomass and fast-growing accumulator plant which has the ability to take up and accumulate metals and radionuclides (Tassi et al 2008;Tahmasbian and Sinegani 2014). Soybean, Glycine max L., produced peroxidase enzymes (McEldoon et al 1995).…”

Remediation of heavy metal contaminated ecosystem: an overview on technology advancement

“…In the process of phytoextraction with the help of chelant, it was applied to the soils. First, chelant can desorb metals from the soil matrix, and the mobilized metals move to rhizosphere for uptake by plant roots (Tahmasbian and Sinegani 2013). The amounts of bio-available metals in soil solution are mainly determined by the properties of the soil and applied chelant (Tandy et al 2004;Luo et al 2005).…”

“…First, chelant can desorb metals from the soil matrix, and the mobilized metals move to rhizosphere for uptake by plant roots (Tahmasbian and Sinegani 2013). The amounts of bio-available metals in soil solution are mainly determined by the properties of the soil and applied chelant (Tandy et al 2004;Luo et al 2005). In order to reduce discharge of metal chelants into ground water and for reducing impact of chelant on soil micro-organisms, its selection, its amount and process of their application are important (Evangelou et al 2007;Luo et al 2007).…”

Chelating Agents and Heavy Metal Phytoextraction

“…Of the organic matters used to improve soil phytoextraction efficiency and soil fertility, manures and their extracts such as cow, sheep, and poultry manures and extracts are more common and used by many scientists (Safari Sinegani and Khalilikhah 2008Safari Sinegani and Ahmadi 2012;Tahmasbian Ghahfarokhi and Safari Sinegani 2013;Tahmasbian and Safari Sinegani 2014). Fresh organic matters such as manures contain soluble organic fractions being able to increase the solubility of metals shortly after adding to soil through the formation of organo-mineral complexes (Almas et al 1999).…”

“…where Cmr shows the concentration of metals in plant roots, although the concentration of metals in shoots can be increased without increasing the TF when changes between the Cmh and Cmr are approximately equal (Tahmasbian and Safari Sinegani 2014). So, in phytoextraction, another factor named enrichment factor (EF) may be estimated according to Eq.…”