| In this experiment, the actual production of wastewater was treated by SBR reactor depth study of a single factor non-cooperative control of short-range effect of nitrification and denitrification factors and running stability. Control were studied DO, pH, SRT, HRT and non-single factor controlling the accumulation of nitrite, and how these factors on nitrification and denitrification system; studied under controlled conditions a single factor non-nitrification denitrification process Organic compounds, ammonia nitrogen removal rate and nitrite accumulation rate, and under controlled conditions to achieve these short-range nitrification and denitrification system stability, and the results of short-range biological nitrogen removal SBR process engineering applications and provide a theoretical basis for real-time control and technical support.Low DO concentration (0.7-1.0 mg/L) to achieve nitrification and denitrification, increase after the initial stage DO, nitrification rate is high, but when the restored activity of bacterial nitrate after nitrification rate decreased rapidly, this time even lower DO concentration, nitrification rate is not high, indicating that the nitric acid bacteria have adapted to the environment and accumulate in the system, the short-term low DO conditions can not inhibit the activity of nitric acid bacteria, then the system has maintained a low DO level, nitrosation rate began to Increased, say nitrate accumulation Minya to recover from the destruction process is long.Ammonia removal rate influenced by the pH value, pH value of 7.5, ammonia removal efficiency rapidly increased to about 67.5%; pH value of 8.0 and 8.5, the ammonia removal efficiency increased slowly to 69.77 and 71.16, little changed, And the final pH values were 6.9 and 7.1, the basic difference is not large, indicating that pH 8.0 or above, only by increasing the pH value, hard to significantly improve the nitrogen removal rate. pH 8.0, the maximum activity of heterotropHic bacteria, which will help the removal of COD, less than this value will decrease its activity, although higher than this value increased but its activity is very obvious, the impact of pH on the ammonia removal efficiency COD removal efficiency than the multi-impact, high or low pH, COD removal rate is not high.With the increase of sludge age, ammonia nitrogen removal rate increased slowly, when the sludge age greater than 20 days, the ammonia nitrogen removal rate decreased age of 15 days in the mud, began to clear the accumulation of nitrite, when the mud Age of 19 days, the maximum nitrite accumulation rate 90%, achieved nitrification and denitrification, when the SRT than 22 days, began to significantly decrease the concentration of nitrite nitrogen, nitrate concentration decreased more slowly, indicating that Nitrite bacteria to changes in SRT responsive, and nitrate bacteria changes in external conditions have lag, and adaptable.HRT alone should be at least maintained under controlled conditions over HRT llh to ensure the removal of ammonia, HRT for the 13h-15, the highest rate of nitrite accumulation of 92%, ammonia nitrogen removal rate basically stable at 80%, achieved nitrification Denitrification; extended to HRT 18h, the accumulation rate of nitrite decreased rapidly to about 75%, indicating that HRT is not conducive to the maintenance of long high nitrite accumulation, an ideal HRT for the 13-15h, then both Can guarantee the ammonia removal efficiency, while maintaining high nitrite accumulation.Comparison of different experimental conditions by running the two SBR reactors (SBR1 control of a single factor, SBR2 a single factor non-controlled) comparative study of nitrification and denitrification to achieve and maintain its stability. SBR1 in low-DO conditions (0.3-0.6mg.L-1) can achieve stable operation of nitrite accumulation rate, but the DO concentration increased to 2.0 mg.L-1 or so, nitrite accumulation rate from 89% to Less than 25%, again to reduce the DO concentration of 0.3-0.6mg.L-1, an increase of nitrification rate is very slow, long-term changes little, experimental form of nitrate accumulation rate Minya to reproduce the recovery from the destruction process is long; SBR2 in the low DO (0.3-0.6mg.L-1), high PH (8.7 or so), a long time to run the SRT condition, the accumulation rate of nitrite up to 93%, and the DO concentration increased to 2.0 in mg·L-1 or so nitrite accumulation rate changes very little; to maintain the sludge age of about 20 days long enough in this sludge age, you can maintain the ammonia-oxidizing bacteria and nitrite-oxidizing bacteria in the system stable growth.Reaction of the SBR system was ammonia-resistant impact test. Test results showed that:the average concentration of ammonia water by the impact of pre-10.8mg /L into a 13.2mg/L, but the average removal rate remains as high as 84.6%; average nitrite concentration and nitrification rate by a 35.1mg/L and 93.6% To 32.6mg/L and 90.2%, although slightly higher than before the test, but look at the entire operation remains a good stability. |
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