Study of biosorption of Zn(II) ions from aqueous solutions by activated mixed biomass of knotweed Reynoutria japonica

Abstract

The ability of mixed biomass (stems and leaves) of an invasive plant Reynoutria japonica to bind up Zn(II) ions has been studied. For modelling of kinetic data, pseudo-second-order model was used. The sorption equilibrium data were described by the Langmuir and Freundlich models; the processes were in concordance with obtained Langmuir and Freudlich isotherms. Both linear and non-linear models were suitable for data modelling. Maximal sorption capacity for Zn(II) was 8.97 mg/g (PAB 0.5). The sorption mechanism explained as ion exchange was described using EDS analyses. The binding groups of leaves and stems of R. japonica biomass were analyzed using FTIR method. For desorption of Zn(II) from R. japonica mixed biomass, 0.2M H2SO4 was successfully used.