Comparative Studies of the Phytoextraction Capacity of Five Aquatic Plants in Heavy Metal Contaminated Water

Abstract

The uptake capacity of the aquatic plants (Salvinia natans Kunth., Eichhornia crassipes Mart., Lemna minor L., Elodea canadensis Michx., Pistia stratiotes L.) was analyzed in phytoextraction of Cu2+, Zn2+, and Cd2+. It was attend to study the plants capacity comparatively using mono and multimetallic systems. In particular, the chlorophyll, protein and carotenoids contents were studied during heavy metals uptake, in order to observe the stress effect on plants. The results obtained for the monometallic system showed that Salvinia natans Kunth. accumulated the highest quantity of Cu2+ (4.72 mg/g), Zn2+ (2.23 mg/g) and Cd2+ (1.90 mg/g). The leaves of Lemna minor L. accumulated the highest concentration of Cu2+ (10.80 mg/g) and Cd2+ (2.78 mg/g) in multimetallic system. The water lettuce (Pistia stratiotes L.) translocated the highest quantity of Zn2+ in its roots (4.80 mg/g). The chlorophyll and the carotenoids levels decreased under the stress of heavy metals in both systems, while protein content increased under the influence of Cu2+ and Cd2+, but decreased for Zn2+.  The studied hydrophytes proved to be useful in the uptake of heavy metals in monometallic system and much more effective in the multimetallic system and showed great potential for further applications in the industrial and commercial wastewater treatments.