Citric Acid and EDTA as chelating agents in phytoremediation of heavy metal in polluted soil: a review

Abstract

Abstract The application of metal chelating agents in phytoremediation has been shown to increase plant efficiency for heavy metal uptake in phytoextraction significantly. EDTA is a famous chelating agent used in phytoextraction. However, future use of EDTA is likely to be limited to ex-situ conditions where leachate control can be achieved, so there are limitations to its use that need to be studied. So that many phytoremediation studies have been carried out on organic chelating agents that are not expected to be harmful to the environment, one of which is Citric Acid. The purpose of this review is to compare commonly chelating agents, namely: EDTA as synthetic and Citric Acid as a natural matter for phytoremediation in polluted soils. This review also discusses the ability of Citric Acid and EDTA on phytoremediation, their effect on soil physiology and soil microbiology, advantages and disadvantages of each on the prospects of phytoremediation. EDTA can increase phytoextraction better than Citric Acid but can increase the risk of groundwater pollution because EDTA is difficult to degrade by the environment. In contrast, Citric Acid has been shown to increase phytoextraction, phytostabilization and harmless to the environment.