Use of phytoremediation techniques for elimination of lead from polluted soils

Alžbeta Hegedűsová,Ondrej Hegedűs,Silvia Jakabová,Andrea Vargová,Tímea Judit Pernyeszi

doi:10.36547/nbc.1217

Abstract

The effect of chelating agent – EDTA (ethylene-diamine-tetra-acetic acid) was used for induced phytoextraction to increase intensity of lead transfer from roots to aboveground parts of garden pea. Pot experiments with contaminated soil substrata (50 mg Pb.kg-1 and 100 mg Pb.kg-1) were established for experimental purposes in growth chamber. The results showed that application of 5 and 10 mmol EDTA.kg-1 to experimental variants with 100 mg Pb.kg-1 doubled the increase of lead uptake by pea roots in comparison with variants without EDTA addition, which was statistically confirmed. Intensive lead transfer was observed from roots to aboveground parts of pea after application of 5 and 10 mmol EDTA.kg-1 in variant with 50 mg Pb.kg-1 (40-fold increase), as well as in variant with 100 mg Pb.kg-1 (17-fold increase). The results showed that induced phytoextraction can improve the mobility of lead from soil to plant roots. Application of 5 mmol EDTA.kg-1 resulted to 40-fold increase of lead transfer to green plant parts, despite the fact, that garden pea does not belong to conventional metal hyperaccumulating plant species. Following the results, pea could be used for decontamination of arable soil. The optimal EDTA concentration seems to be 5 mmol.kg-1. Therefore, application of 10 mmol EDTA.kg-1 decreased root mass about 55%, which resulted to decrease the intensity of lead uptake.

Highlights

The territory of Slovakia belongs to long term polluting areas with transfer of contaminants from large industrial and power plant complexes with regional effects
Transfer of lead did not continue from roots to aboveground parts of plant in variant without application of EDTA
The results showed that concentration of 5 mmol EDTA.kg-1 enhanced Pb transport from roots to aboveground parts 33-times in variant with 50 mg Pb.kg-1

Summary

Introduction

The territory of Slovakia belongs to long term polluting areas with transfer of contaminants from large industrial and power plant complexes with regional effects. These negative effects affect an extraordinary heterogenous soil cover and increase the content of risk elements to amounts exceeding their limits. Accumulation of risk elements in soils affects its ability to produce hygienically unobjectionable foodstuffs, which applies especially for the content of heavy metals with a high degree of biotoxicity from various sources (HEGEDŰSOVÁ et al, 2000). Generally called phytoremediation offer possibilities of removing heavy metals from soils (HUANG and CUNNINGHAM, 1996; LASAT, 2002; SIMON et al, 2003). The most often used phytoremediation techniques are especially phytoextraction and phytostabilitation

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Conclusion