Pressurized oxygenation system and method

Abstract

A system for performing an oxygenation process within a body of sewage at atmospheric pressure includes an oxygen absorber coupled to an oxygen supply at superatmospheric pressure. A storage vessel has an elongate chamber therein which is oriented vertically in the system. Pipes and valves are coupled to the upper and lower ends of the chamber so that the chamber is alternately communicated with the oxygen absorber and the body of sewage, thereby providing alternate high pressure and low pressure half cycles respectively. Initially, oxygenated liquor at superatmospheric pressure is in the oxygen absorber and the elongate chamber is filled with a quantity of low oxygen content liquor at atmospheric pressure. The valves are then operated during the high pressure half cycle to admit oxygenated liquor into the elongate chamber through the lower end and to simultaneously expel liquor and undissolved oxygen from the upper end into the oxygen absorber. The valves are then operated during the low pressure half cycle to reduce the chamber pressure to atmospheric and to admit a quantity of liquor from the body of sewage into the elongate chamber through the top end while simultaneously expelling the oxygenated liquor from the bottom end into the body of sewage. Thus, oxygen which comes out of solution and collects as relatively large bubbles as the pressure in the chamber is reduced to atmospheric pressure, will be retained in the elongate chamber and returned to the oxygen absorber during the next high pressure half cycle. A preferred embodiment of the invention includes two or more storage vessels alternately operated during the high and low pressure half cycles to provide a substantially continuous flow of liquor into and out of the pressurized oxygen absorber.