Effects of Surface Modification of Magnesium Anode on Electrochemical Precipitation of Magnesium Ammonium Phosphates

The surface of magnesium (Mg) electrode was been modified by immersion pre-treatment of Mg in aqueous solution containing nano-sized inorganic particles, silica or layered double hydroxide (LDH), and a polymer for improving electrochemical phosphate ion removal from synthetic wastewater.Among the tested inorganics, polymers, and compositions, immersion pre-treatment in a solution containing nano-sized silica and poly(ethylene glycol) (PEG) (silica content of ca.0.4%) provided the highest electricity, the highest removal of phosphate ion, and the quickest formation of precipitate.Highly dispersed silica particles could enhance mass transfer at the interface region and increase phosphate ion conversion into magnesium ammonium phosphates (MAPs) through the enhancement of electrochemical reactions.