The present invention relates to a process for treating a wastewater comprising an ammonium ion species and a phosphorus ion species. A per-instance in-memory dispenser is partitioned. One or more adjustable pushdowns having airbags attached to their heads are provided to grip a load between the pushdown and pickup arm. A removable tray has second openings therethrough a second membrane having pores is slidably provided on the lower surface of the removable tray to either keep tablets in the second openings thereby or drop the tablets through the pores thereof when slidably displaced to a predetermined extent. On the other hand, when a moving image is displayed, an applied voltage corresponding to a predetermined gradation m ) is applied to the pixels instead of applied voltages respectively corresponding to gradations of less than the predetermined gradation m.