Treatment of organic waste liquor containing ammonia nitrogen

Abstract

Abstract PURPOSE:To treat organic waste liquor in an extremely simplified process with the saved consumption of energy, by evaporating water formed in the biotreatment of said waste liquor in the step of evaporation with indirect heat, and removing residual NH3 nitrogen in condensed water formed from the evaporated steam in the step of removing NH3 nitrogen. CONSTITUTION:Scum-removed night soil 1 is let flow as such into the step 2 of biological nitrification-denitrification, to mainly remove N components such as BOD and NH3. Active sludge slurry 3 flowing out of the step 2 is then separated into a liquid and solid matter in the step 4 of solid-liquid separation such as a centrifugal thickener. The major part of the separated sludge 5 is circulated as returned sludge 6 to the step 2. On one hand, the separated liquid 7 in the step 4 is let flow into the step 8 of evaporation, preheated at about 80 deg.C with the condensed water 10 of steam in a heat exchanger 9, thickened by evaporation and then discharged as a conc. liqud 11. On the other hand, the steam 12 formed in the step 8 is compressed to raise its temp. by a steam compressor 13, fed to the indirect heating part 14 of the step 8 and reused therein as a heat source. Thereafter, the condensed water 10 obtd. at the heating part 14 is passed through the heat exchanger 9 and then fed to the step 15 of removing NH3 to completely remove remaining NH3 nitrogen.

Inventors

• 👤 Katsuyuki Kataoka
• 👤 克之 片岡

Bibliographic Details