帮我改写：an electric field was applied between the adsorption electrode and an air cathode which caused the migration of phosphate anions towards the sacrificial anode Subsequently current was applied bet

By employing an electric field, phosphate anions were induced to migrate towards the sacrificial anode from the adsorption electrode and air cathode. This was followed by the application of current between the air cathode and the sacrificial anode (constructed with either Fe or Al mesh), which facilitated the electrocoagulation process for phosphate.