Study On Black Water From Passenger Trains Treatment With SBR Prcess

The sewage of Sealed Toilet of Passenger Train is high concentration fecal sewage. It has the characteristic of high concentration of organic compounds, high strength ammonia - nitrogen, high suspended solids, low C/N, big change in water quality. It is very difficult to be dealt with. The high efficiency of denitrification is the key to deal with the sewage of Sealed Toilet of Passenger Train. "screen filtration-ABR-SBR- anaerobic ammonium oxidation-SBR" combination technology is used to research and manage the sewage of Sealed Toilet of Passenger Train. At the same time, Nitrous Nitrifying experiment and Advanced Treatment Technology have been used in the two-stage of SBR technology, and have got a good result.Nitrous Nitrifying experiment of SBR indicates that if we want to have the result of water-exit NH₃-N:NO₂^--N approaching to 1:1 in the Nitrous Nitrifying experiment. The best Operating Condition is: when the concentration of influent ammonia nitrogen≤2000 mg/L, Feeding- Aeration (5h)→Sedimentation (1h)→Draining (0.5h)→Idling (0.5h) . when the concentration of influent ammonia nitrogen>2000 mg/L, Feeding-Aeration (6h)→Sedimentation (1h)→Draining (0.5h)→Idling (0.5h) . The best pH is 7.7 and the optimal DO is 2.0mg/L. There is no significant operation result difference when the temperature between normal temperature (25℃) and high temperature (35℃) .So we do not need to heat the wastewater during operation. The total nitrogen lose approximately is 10%, because of Blow-off effect and SND effect during nitrification process. And the loss quantities have a relation between the concentration of DO and pH. When the concentration of DO is between the range of 0.5～1.5mg/L, the total nitrogen removal rate has a positive relationship with DO. There is a significant nitrogen removal rate change when the pH rise from 7.0 to 7.5. And there is no significant change, when the pH rise from 7.5 to 8.0. The acclimated activated sludge system has a high endurance to free ammonia, and it can reach 70 mg/L; and all the nitrate bacteria almost eliminate in the acclimated activated sludge. There is no NO3—-N accumulation, when we enhance the DO concentration during operation. Advanced Treatment Technology of SBR indicates that the best operation condition is: Feeding(1h)- Aeration (6h)→Anaerobic agitation (2h)→Back aeration (1h)→Sedimentation (1h)→Draining (0.5h)→Idling (0.5h) .After the aeration, the effluent water COD_Cr <150mg/L, and it satisfy the second criterion of "Comprehensive Sewage Discharge Standards" (GB8978—1996 ) .The residual COD_Cr is almost all the difficult biodegradation organic compounds. Even we extend the aeration time; they are also hard to remove. The effluent water ammonia nitrogen <15mg/L, and it content to the first criterion of "Comprehensive Sewage Discharge Standards" (GB8978—1996) . During the denitrification, because the concentration of ammonia nitrogen in the raw sewage is too high, so we can not use it as external carbon source. In this experiment condition, if we use glucose as external carbon source, so the periodical theoretical dosage is 152.07g.