NOVELTY - The activated sludge process equipment has a natural-water adjustment tank (2), a denitrifying tank (3), a nitrification tank (4), and membrane-filtration units. The equipment biologically processes wastewater and membrane-separates to activated sludge and treated water. The adjustment tank is equipped with a level gauge (25) for setting the liquid level of adjustment tank, and a controller for automatically increasing the amount of suction of filtered treated water from the membrane-filtration unit corresponding to the liquid-increase velocity.    USE - For processing organic wastewater, such as daily-life wastewater and industrial wastewater.    ADVANTAGE - The activated sludge process equipment rapidly processes organic wastewater even when the liquid quantity of each processing chamber increases abnormally. The processing capacity of the nitrification tank is increased. Since natural water of the adjustment tank is sent at high speed according to the increase in suction velocity of the filtration pump, overflowing from the adjustment tank is prevented.    DETAILED DESCRIPTION - The activated sludge process equipment has a natural-water adjustment tank (2) for adjusting the inflow of natural water to denitrifying tank (3), a denitrifying tank for carrying out denitrification processing by denitrifying bacteria, a nitrification tank (4) for nitrification processing by nitrifying bacteria, and set(s) of membrane-filtration units immersed in the nitrification tank. The equipment biologically processes wastewater and carries out membrane separation to activated sludge and treated water. The natural-water adjustment tank is equipped with a level gauge (25) for setting the liquid level of natural-water adjustment tank, and a controller for automatically increasing the amount of suction of filtered treated water from the membrane-filtration unit corresponding to the liquid-increase velocity.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic block diagram of the separation-membrane activated sludge process equipment. (Drawing includes non-English language text)    Screen (1)    Natural-water adjustment tank (2)    Denitrifying tank (3)    Nitrification tank (4)    Liquid gauge (25)