Reactive metal oxides in ceramic membrane formulation as a clue to effective point-of-use drinking water defluoridation

The potentials and feasibility of incorporating reactive metal oxides in ceramic membrane formulation for the development of an efficient point-of-use (POU) drinking water defluoridation system has been systematically interrogated herein. The trend in the POU water defluoridation and the use of ceramic membrane as POU water treatment system were expounded to provide the state of the art. The intrinsic features of metal oxides vis-à-vis the theoretical basis that enables them to show high affinity for aqua phase fluoride were highlighted. The preferred metal oxides for aqua defluoridation were discussed, and perspective on the feasibility of incorporating metal oxides in ceramic membrane as POU water defluoridation system was presented. The powdery physical nature of metal oxides, which is a general limitation to the use in both batch and column water treatment operations can be circumvented through the inclusion in the porous ceramic membrane support. Tailor-made solutions should be developed to the identified specific limitations (e.g., toxicity, high cost) that limit the inclusion of any metal oxide of interest in the ceramic membrane for drinking water defluoridation.