APPARATUS FOR PURIFICATION OF FILTHY WATER

PURPOSE:To effectively supply oxygen necessary for biologically purifying action, by providing a reaction tank equipped with an overflow trough for withdrawing treated water from a position in the vicinity of a liquid surface and one or more circulation means inside said reaction tank. CONSTITUTION:When highly conc. oxygen gas is sucked from an oxygen gas supply pipe 12 through a sparger 13 into a liquid inside a bubbler pipe 5, the liquid is raised inside the bubbler pipe 5 by the boiling-up motion of the gas. Hence, filthy water supplied through a filthy water supply pipe 15 and a sludge- contg. liquid sucked in through a sludge-sucking trough 14 are let flow through a passage 8 and the opening 9 of the bubbler into the bubbler pipe 5. During the rising motion of the liquid together with the bubbles of the highly conc. oxygen gas inside the bulbbler pipe 5, the liquid absorbs the oxygen gas. Thereafter, the liquid flows over the upper end of the bubbler pipe 5 into a zone 16 for gas- liquid separation, so that unabsorbed gas is separated from the liquid and discharged through a drain pipe 18.