TREATMENT OF EXCRETION SEWAGE

• Main Authors: ISHII YASUHIKO, MURAKAMI YASUNOBU
• Format: Patent
• Language: English
• Published: 18.10.1985
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PURPOSE:To enhance a COD removal ratio and a nitrogen removal ratio, by adding a flocculant to excretion sewage after anaerobic treatment is applied thereto to perform flocculative separation and applying biological nitration and denitrification treatment to the separated solution. CONSTITUTION:Excretion sewage 7 is introduced into an anaerobic tank 1 and anaerobic treatment is performed to convert a part of SS like and high-molecular BOD to soluble BOD. Next, sewage is introduced into a first reaction tank 2a and an inorg. flocculant and/or a cationic org. flucculant 8 is injected into said reaction tank 2a while a nonionic or anionic org. flocculant 10 is injected in a second reaction tank 2b if necessary to grow floc and solid-liquid separation is performed by a solid-liquid separation means 3. Subsequently, the separated solution is introduced into a denitrification tank 4 along with return sludge 13 and a return nitrated solution 14 and mixed with activated sludge containing denitriding bacteria to perform denitrification treatment in an oxygen blocked state. Further, the treated solution is introduced into a nitration tank 5 to perform aeration treatment.