PROCESS FOR REMOVING SCUM LAYER, SPRAY NOZZLE FOR SCUM LAYER REMOVAL AND BIOLOGICAL REACTION VESSEL

摘要

PROBLEM TO BE SOLVED: To provide a process for inhibiting the formation of a scum layer, which inhibits formation of a scum layer in a sewage treatment facilities, also to provide a spray nozzle for removing a scum layer or inhibiting a scum layer from being formed and further to provide a biological reaction vessel provided with the spray nozzle. SOLUTION: This process involves: horizontally jetting washing water so as to form a sectorial flow shape, from a spray nozzle 14 almost immersed below the water surface of a section in which deposition of scum and formation of a scum layer are liable to occur, such as water conduit 2a or biological reaction vessel, in sewage treatment facilities; thereby forming a surface current flowing from the rear side of the spray nozzle 14 in the washing water jetting direction, in such a way that sewage is sucked from the rear side of the spray nozzle 14 by means of the nozzle 14; and breaking the scum with the washing water jetted from the spray nozzle 14, to inhibit any scum layer from being formed.