Kinetic studies using a linear regression analysis for a sorption phenomenon of 17a-methyltestosterone by Salvinia cucullata in an active plant reactor

The aim of this study was to investigate the removal efficiency of  17α-methyltestosterone (MT)  from an aqueous solution by  Salvinia cucullata Roxb.  ex Bory in an active plant-based reactor with a specific focus on linear regression analysis for the sorption phenomena of MT  onto the plant roots.  A high-performance liquid chromatographic method using  UV  detection  (245  nm)  was used to analyse the samples.  The batch experiments of the active plant reactor (APR)  were established to investigate the ability of  Salvinia cucullata to remove  MT  from the liquid phase.  The results revealed that 40%  and 60%  removal of  MT  from the liquid phase was observed at 5 min. and at  4  h,  respectively.  Salvinia cucullata can effectively remove  MT  from the aqueous solution in  APRs.  Kinetic studies revealed that the sorption phenomena of  MT  by  Salvinia is best described using a linearized pseudo-second-order model.  Based on the kinetic parameters, it is likely that during the first 4  h  of the contact  (t  = 0 to t  = 4 h)  sorption is the major driving mechanism of the disappearance of  MT  from aqueous solutions.  However,  at higher  MT  concentrations, the diffusivity of  MT  has a  significant effect on the migration of  MT  from the bulk stream to the root surface.  The isotherm analysis revealed that the sorption kinetics favourably followed pseudo-second-order. The results of isotherm analysis have indicated that the sorption of  MT  onto the root surfaces of  Salvinia cucullata was favourable and almost irreversible.