Can prolonged aeration lead to a decrease in the pH value of the biochemical tank?
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Dear experts, the original COD concentration of the water entering our plant is 110 mg/L, the ammonia nitrogen level is 14 mg/L, and the TN level is 20 mg/L. The sludge concentration was 2000 mg/L. No water was added for 55 hours; during the first 20 hours, aeration was continuous, and the DO level increased from 0.8 mg/L to 6.4 mg/L. In the subsequent 35 hours, aeration took place for 2 hours followed by 4 hours of no aeration, with an average DO level of 6 mg/L. The AAO process is in normal operation, along with the external recirculation system and the secondary sedimentation tank. Question: The nitrification of ammonia nitrogen consumes alkalinity; under the above process conditions, will this lead to a decrease in the overall pH of the biological treatment tank? ?
The pH value will drop, but it won’t go below 6.5. Judging from the ammonia nitrogen levels in the water, it is not expected to drop significantly.