(cest2017_00363) Copper uptake by Chrysopogon zizanioides (L.) Roberty from aqueous solution: Effects of different factors and kinetic study

摘要

The high biomass, extensive root network, and fast growthof vetiver grass [Chrysopogon zizanioides (L.) Roberty]make it a good candidate for the treatment of heavy metalpollutedsoil and water. For this reason, the influence ofcopper (Cu) concentration, iron (Fe) concentration, andpresence of citric acid (CA) as chelating agent on the Cuaccumulation in the roots and shoots of vetiver grass wereinvestigated using a 23 factorial design. Moreover,Michaelis-Menten equation was utilised to describe theuptake of Cu after 24 hours. Vetiver grass was grownhydroponically using half-strength Hoagland solutionadjusted to pH 4 and different conditions for the factorialexperiment or varying Cu concentration for the kineticexperiment. Results indicate that the effects of Cuconcentration on the Cu uptake of both roots and shootswere highly significant as determined by ANOVA.Meanwhile, there were significant interactions of Cu andFe concentrations, Cu and presence of CA, and Feconcentrations and presence of CA on root Cu uptake only.For the kinetic study, the Michaelis-Menten equation wasfound adequate implying a saturable transport system. Thecalculated Michaelis-Menten constant, Km, and maximumsolute uptake influx, were Vmax, 24.39 mg L- and 272.21mg kg FW- day-, respectively.