Oriented Membrane Processes for the Treatment and Recovery of Vanadium Ions from Industrial Acidic Solutions

The extraction and recovery of vanadium through polymer inclusion membrane, based on β-cyclodextrin or c-methyl resorcin[4]arene as a carrier, with polyvinyl alcohol as polymeric matrix and Tributylphosphate as plasticizer from acidic medium has been carried out. Different kinetic and thermodynamic parameters for correspondence to the mathematical model was studied. Macroscopic parameters, vis. the permeability and the initial flow, which indicate the performance of the membrane, have been investigated, as well as the microscopic parameters, expressed by the association constant; relating to the substrate-carrier interaction, and the diffusion coefficient which belongs to the movement of VO₂⁺ ions through the membrane have been determined. The temperature parameter has been studied and it presents a significant effect on the extraction rate (activation energy is 19.58, 15.24 kJ · mol⁻¹ for β-cyclodextrin and c-methyl resorcin[4]arene, respectively), improving the diffusion rate of reactants. The analysis of all the studied parameters allowed us to confirm the mechanism by jumping on semi-mobilized sites of the carrier in the organic phase. Moreover, this study opens a new way for the use of facilitated transport and manipulates the efficiency of the carrier in order to develop an ecologic membrane with high performance for the recovery of metals from wastewater, in order to reduce the environmental impact due to their toxicity with high concentrations in the ecological system.