The invention discloses a deep treatment technique used for the printing and
dyeing sewage recovery. The technique consists of a BAF pond, an air-bearing
system, an
ozone contact oxidation
tower, a filter, an
active carbon filter, an
ozone generator and a
medicine adding
system. The technique is the improvement of the traditional BAF technique, removes the resolvable
organism in the
sewage through the biological degradation, outtakes the water into the air-bearing
system and combines the
flocculation medicine adding technique, so as to eliminate the non-
solvent organism and colloidal substance in the
sewage. The outtaken water enters into the
ozone contact oxidation
tower and gets mixed with ozone, so that the
organism which is difficult to undergo the biological degradation in the printing and
dyeing sewage is removed with the help of the strong oxidizing property of the ozone. The water flowing out of the ozone contact oxidation
tower enters into the pond at the middle, and 30 percent of the water returns to a gas dissolving can under the action of a pressurizing pump, gets mixed with the pressurized air and then enters into the air-bearing system through utilizing the remaining pressure. The gas-water solution is dispersed into the small and equable drips through a dissolved gas releaser, and the drips drive the suspending substances and the colloidal substance to float up to the water surface so as to achieve the removal. The water
coming out of the middle pond enters into the filter to remove the small suspending substances and enters into the ozone /
active carbon filtering system so that the reaction of the ozone basic chain is caused under the action of the
active carbon, thereby speeding up the
decomposition of the ozone into OH and other free radicals, degrades a small amount of organism, eliminates the color and finally ensures that the outtaken water reaches the
recovery standard of the printing and
dyeing sewage.