Semi-process Experiment Of Sludge Concentration In District Of Junshan No.2 Wasterwater Treatment Plant

In the A²/O process,the sludge reflux ratio is usually increased to increase the sludge concentration in the biochemical pool.However,the concentration of the return sludge is affected by the size of the second settling tank and the sedimentation time,which is difficult to increase unilaterally,so most urban sewage plants are exposed.The concentration of sludge in the gas pool is 2000⁴000mg/L.When the influent concentration exceeds the designed influent water,the effluent is difficult to reach the standard discharge.Aerobic Granular Sludge（AGS）has the characteristics of good sedimentation performance and high sludge concentration.According to the principle of“crystal nucleus hypothesis”,a specific size（diameter 1-2 mm,spherical shape）and mass are added to the reactor.The inert core or dry sludge particles with good adhesion can accelerate the process of aerobic granulation of sludge,overcome the problem that AGS culture takes a long time and the shape is difficult to maintain for a long time,and finally forms AGS.Therefore,the addition of a specific selected inducing nucleus to the aerobic active granular sludge in the aeration tank of the municipal sewage plant can improve the decontamination ability of the pool under the unit volume of the biochemical pool.In the laboratory treatment of simulated wastewater,the granular sludge was inoculated into the SBR reactor containing flocculent sludge for continuous cultivation,the simulated wastewater was degraded,and the water was taken out for water quality testing.After the sludge was thickened,the effluent water quality became better.The concentration of pollutants decreases,and the removal rate of pollutants becomes higher.The results of the sludge thickening（semi-）process wastewater test showed that after 27 days of continuous culture,the flocculating sludge could co-process the actual wastewater with the granular sludge,and the MLSS in the SBR reactor reached6400 mg/L.The MLSS in the aeration tank is only 3100 mg/L,and the COD removal rate of both is greater than 95%,but the removal rate of NH₄⁺-N in the SBR reactor is over 90%,only about 80%in the wastewater treatment plant,and the TN removal rate of the wastewater treatment plant is 60%.About%,and the TN removal rate in the SBR reactor can reach 71⁹4%.It is speculated that about 3g of granular sludge is added per 1 L of mixed water,and the TN removal rate of the system is increased by about 18%to 34%,mainly due to the special structure of the granular sludge capable of simultaneous nitrification/denitrification,and the physical properties of the particles are basically It is stable,resistant to toxic and anti-load shocks and has strong decontamination performance.In summary,this test proves that by cultivating aerobic granular sludge and increasing sludge concentration,the ability of aerobic tanks to treat actual wastewater in the A²/O process can be improved.This technique is suitable for treating domestic wastewater by ordinary activated sludge process.The post-process upgrade and upgrade of the plant can also reduce the project investment cost while enhancing the decontamination capacity of the system.