Removal of As, Cd, Pb, and Zn from contaminated soil by high biomass producing plants
Tlustoš, P; Száková, J; Hrubý, J; Hartman, I; Najmanová, J; Nedelník, J; Pavlíková, D; Batysta, M
The uptake of As, Cd, Pb and Zn by five high biomass producing crops (Melilotus alba, Trifolium pratense, Malva verticillata, Carthamus tinctorius and Cannabis sativa) commonly used as grazing and/or energy crops was determined and evaluated in both pot and field experiments at soils with different level of element contamination to assess the potential suitability of these plants for phytoremediation. Cambisol (Soil B) with moderate contamination mainly caused by atmospheric emissions from the smelter, and unpolluted Chernozem (Soil A) were used. An extremely contaminated Soil C was soil A spiked by 100 mg/kg AS, 40 mg/kg Cd and 2000 mg/kg Pb as aqueous solutions of Na2HAsO4, CdCl2, and Pb(CH3COO)2, respectively. The vicinity of the smelter belongs to the most damaged areas in the Czech Republic. Three levels of element contents in soil in the field experiments were: Level 1 - control without addition of elements resulting in total contents 1.6 mg/kg Cd, 60 mg/kg Pb and 95 mg/kg Zn; Level 2 - final element content in soil resulting in total contents of 10 mg/kg Cd, 1000 mg/kg Pb, and 400 mg/kg Zn; and Level 3 - final element content in soil resulting in total contents 40 mg/kg Cd, 4000 mg/kg Pb, and 1000 mg/kg Zn. In pot experiment, the highest phytoremediation efficiency was demonstrated by C. tinctorius where 4.8% of Cd and 1.1% of Zn were removed from the moderately contaminated soil in one vegetation period when repeated harvest of aboveground biomass was performed. The removal of As and Pb was negligible for all the investigated plant species. At the highest element content in soil, inhibition of plant growth due to the element phytotoxicity of plants was reported in most cases. In the field experiment, lower phytoremediation efficiency (biennial phytoremediation factors did not exceed 0.2% for Pb and Zn, and 0.3% for Cd for C. tinctorius) was determined, but yield suppression was not observed.
arsenic; biomass production; cadmium; Cambisols; Chernozems; hemp; lead; phytoremediation; polluted soils; safflower; soil pollution; soil types; zinc; Cannabis sativa; Carthamus tinctorius; Malva verticillata; Melilotus alba; Trifolium pratense; Cannabis; Cannabidaceae; Urticales; dicotyledons; angiosperms; Spermatophyta; plants; eukaryotes; Carthamus; Asteraceae; Asterales; Malva; Malvaceae; Malvales; Melilotus; Papilionoideae; Fabaceae; Fabales; Trifolium; black earths; Forage and Fodder Crops (FF007) (New March 2000); Soil Chemistry and Mineralogy (JJ200); Pollution and Degradation (PP600); Industrial Wastes and Effluents (XX400)
