Electrosorption ceramic based membranes for water treatment

The preparation of inorganic electrosorption membranes for the removal of i ons from aqueous solutions is described. The preparation of electrosorption membranes included carbonization of a-alumina porous substrates and gold s puttering to obtain the desired conductivity. Anion and cation adsorption p roperties were subsequently created by incorporation of zirconia and zircon ium phosphate into the pores of the conductive substrate. Results of experi ments carried out on the electrosorption membrane with a model solution of 0.01 M calcium sulfate showed removal efficiencies greater than 90% for bot h ions simultaneously. Regeneration (desorption of ions) was possible by ch anging the polarity of the membrane. No pressure increase due to the format ion of insoluble salts after regeneration was detected after several adsorp tion-desorption cycles. Such electrosorption membranes can be used for micr ofiltration and desalination, simultaneously. Electrosorption membranes hav e the potential to compete with conventional electrodialysis systems in cas es where the formation of insoluble salts or poor thermal and chemical stab ility lead to a significant increase in the cost of the process. (C) 2001 E lsevier Science B.V. All rights reserved.