Bioaccumulation of Multi-metals and Associated Oxidative Stress in Salvinia molesta D.S. Mitchell

Abstract

In the present investigation, three sets of hydroponic experiments were designed to explore the bioaccumulation abilities of multi-metals in the aquatic weed plant, Salvinia molesta. In these experiments, one set of plants was treated with fly ash, a second set of plants wastreated with multi-metal solution (1 mM concentration) which was prepared by mixing salts of different metals in a nutrient solution, and in the third set, plants were kept in a nutrient solution without any exposure for control data. Metal accumulation in plants wasobserved in all three sets. However, S. molesta proved to be highly efficacious for copper (Cu) and chromium (Cr) removal (>50%), and to a lesser extent for zinc (Zn) (34–44%), lead (Pb) (35-54%), nickel (Ni) and cobalt (Co) (below 30%) elimination from both the contaminatedwaters. The biomass was also reduced by up to 17.8 % in multi-metal solution as compared to the control. A slight increment in biomass of fly ash treatment indicates the availability of essential elements through metal-endowed fly ash. Reduction in chlorophyll contentsw content in multi-metal solution indicates oxidative stress generated due to membrane damage. Overall outcomes accrued through this study evinced that Salvinia molesta could be exploited in the simultaneous accretion of multiple metals from tainted wastewater.It could also be utilized as an ecological indicator in the assessment of metal-contaminated habitats.