The invention relates to a method for removing impurities from an aqueous stream. Information pertaining to the state of the system at the time a failure occurred on a mobile device is accessible by a developer in a disconnected mode. In the job processed in the scan-all-first mode, insertion of the sheet or insertion of a composite image including the form image is performed according to the settings made in the intermediate state. The metal material of the nozzle member includes crystal particles having an average particle diameter which is less than that of the crystal particles included in the metal material of the flow path member.