The Study To The Optimal Controlling Condition Of Auto-anaerobic Bacterial Removing Nitrogen Technology

Plenty of experiments,theoretical analysis and application research on this object have been performed,and have bought about a lot of results by many investigators. On the base of summarizing the results, adopting theoretical education and experimental analysis, ascertained the best condition of reactive control about a part of influencing factor.First of all, the start-up of the nitrous nitrification bioreactor was tried out successfully. The parameters of the nitrous nitrification fed with synthetic wastewater were as follows: operating temperature 36 degree, pH value 8.0. According to adjusting to the quantity of air feed, the laboratory-scale nitrous nitrification bioreactor was successfully started up. The whole process took up a month.To identify the best condition of reactive control which are pH value and DO(Dissolving Oxygen )in the nitrous nitrification bioreactor.Experimental study on impacts of pH on nitrosation: The experiment carried on in the SBR (sequencing batch reactor), with the temperature controlled at 37 degree. First, reducing the pH value, made the theoretical proportion of NH₄⁺ to NO₂^- in effluent turning to 1:1 approximately, made this situation lasting for a week. Then, rising the pH value, made the theoretical proportion of NH₄⁺ to NO₂^- in effluent turning to 1:1 approximately. This experiment came to a conclusion: When DO is 1mg/L and temperature is 36 degree, pH is not a key factor to retrain nitrosation but the basicity is. By controlling basicity, it can control the proportion of concentration about NH₄⁺-N and NO₂^--N in effluent to get 1:1 approximatelyt.By the time, it can control the cycle of operation to gain a cycle, which academic proportion of concentration about NH₄⁺-N and NO₂^--N in effluent is 1:1.Experimental study on impacts of DO on nitrosation: Reducing the DO to about 0.1mg/L, then elevating the concentration of DO gradually. The density of the water which enters into the reactor is 800mg NH₄⁺-N/L and maintain pH at 8.0～8.3, the temperature at 1cemtograde above or below 36. In the condition, reaction test has carried out 7 days, the test result in indicated when the concentration of DO is smaller than 0.5mg/L, it may produce innibitory action to nitrosation reaction. This conclusion is different from the nether two conclusions, which was TeiSilkel and others said that it has no effect with the rate of nitrosation reaction when the concentration of DO was lower than 0.5mg/L. Also the conclusion was confirmed in Balmelle and yang,s research, that was the height of concentration of DO had no decisive effect to the accumulation of nitrogen in nitrification system.