NOVELTY - An improved cyclic activated sludge technology (CAST) equipment and technology comprises a biochemical aeration blower (1), pool bodies (2), immersion-typed hollow fiber ultra-filtration membranes (3), a membrane washing aeration blower (4), valves (5) and an ultra-filtration discharge pump (6).    USE - As an improved cyclic activated sludge technology (CAST) equipment and technology (claimed) for treatment of sewage.    ADVANTAGE - The present CAST technique not only has the independence and simple operability, but also improves removal of nitrogen and phosphorus, impact load resistance and water outlet stability of the system; omits precipitation stage, which can effectively shorten the period time of the CAST process; and improves treatment of sewage.    DETAILED DESCRIPTION - An improved cyclic activated sludge technology (CAST) equipment and technology comprises a biochemical aeration blower (1), pool bodies (2), immersion-typed hollow fiber ultra-filtration membranes (3), a membrane washing aeration blower (4), valves (5) and an ultra-filtration discharge pump (6). The biochemical aeration blower is connected with several pool bodies. The several immersion-typed hollow fiber ultrafiltration membranes are arranged at the tail ends in the several pool bodies; and are connected with several valves. The valves are connected with the ultra-filtration discharge pump. The membrane washing aeration blower is connected with the several pool bodies. The improved technology comprises use of immersion-typed hollow fiber ultra-filtration membranes to replace decanters in the CAST technology; omits the precipitation stage in the original CAST technology; and makes one operation period to be composed of feeding water, aeration and pumping three stages.    DESCRIPTION OF DRAWING(S) - The figure shows schematic view of an improved cyclic activated sludge technology equipment and technology.    Biochemical aeration blower (1)    Pool bodies (2)    Immersion-typed hollow fiber ultra-filtration membranes (3)    Membrane washing aeration blower (4)    Valves (5)    Ultra-filtration discharge pump (6)