Electrosorption ceramic based membranes for water treatment

The preparation of inorganic electrosorption membranes for the removal of ions from aqueous solutions is described. The preparation of electrosorption membranes included carbonization of a-alumina porous substrates and gold sputtering to obtain the desired conductivity. Anion and cation adsorption properties were subsequently created by incorporation of zirconia and zirconium phosphate into the pores of the conductive substrate. Results of experiments carried out on the electrosorption membrane with a model solution of 0.01 M calcium sulfate showed removal efficiencies greater than 90% for both ions simultaneously. Regeneration (desorption of ions) was possible by changing the polarity of the membrane. No pressure increase due to the formation of insoluble salts after regeneration was detected after several adsorption-desorption cycles. Such electrosorption membranes can be used for microfiltration and desalination, simultaneously. Electrosorption membranes have the potential to compete with conventional electrodialysis systems in cases where the formation of insoluble salts or poor thermal and chemical stability lead to a significant increase in the cost of the process. (C) 2001 Elsevier Science B.V. All rights reserved.