SHIP WASTE WATER TREATING WITH FLOTATION AND MEMBRANE PERMEATION

摘要

The present invention related to a method and an apparatus for treating waste water for ships, and an apparatus for treating waster water on ships in a closed system. The waste water flows upwards through a liquid-solid separation column having a plurality of downwardly slanting bubble generating plates projecting alternately from opposed inner walls of the column. A small space is formed between the free end of each of the plates and the inner wall opposed to it. Each of the bubble generating plates includes an open cellular plate-like member and a pressurized gas distributing channel formed within the plate-like member and extending substantially parallel to the plane of the member. Suspended solids are separated from the waste water in this column and are accumulated in a concentrated state beneath of the plate-like members by flotation with bubbles generated in the bubble generating plates. The suspended solids are reduced to below 1,000 ppm and the resulting treated water is clarified by passing it through a semipermeable membrane treating system.