Removal of potentially toxic elements by Salvinia molesta (giant salvinia), Pistia stratiotes (water lettuce), and Ludwigia adscendens (water primrose) cultivated hydroponically in industrial wastewater

This study assesses the ability of Salvinia molesta, Pistia stratiotes, and Ludwigia adscendens to remove metals from industrial wastewater using hydroponic culture. Industrial wastewater samples showed declining water quality parameters and potentially toxic metals above standard values. Chromium, cadmium, copper, zinc, nickel, and lead concentrations in plant samples were found as root > leaf and increased with effluent strength (100%>50%>control). The perceived bioaccumulation factor (BAF), translocation factor (TF), and metal extraction rate (MER) indicated that Cr, Cd, Cu, and Pb uptake followed the order as S. molesta > P. stratiotes > L. adscendens. S. molesta was most effective at extracting lead (85% removal, BAF = 22967, MER = 7751.6), while L. adscendens was most efficient for Cd absorption (78.8%), and P. stratiotes excelled in removing Cr (80.8%), Cu (78.3%), and Zn (BAF = 22206, TF = 91) from 100% effluent. Metals removal was significant (p S. molesta and L. adscendens, and root versus leaf of S. molesta and P. stratiotes at 100% effluents. The evaluated macrophytes demonstrated significant removal of metals, functioned as hyperaccumulators (BAF > 100), adhering to the sequence BAFroot/water > BAFleaf/water > TFleaf/root. This accumulation pattern boosts removal efficiency and underscores their significant role in improving water quality.