The issue of abnormally high ammonia nitrogen levels in petrochemical wastewater treatment
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Recently, ammonia nitrogen levels in the refining wastewater treatment process have risen abnormally and show no sign of decreasing. The ammonia nitrogen level in the effluent from the air flotation tank is 30-40, but after passing through the biochemical tank, it rises to 50-60. The temperature of Pool O is 35–40°C; under microscopic examination, ciliates that are round or oval-shaped with one pointed end can be seen. The quality of microscopic observations is not as good as before, and the number of microorganisms has decreased. Currently, the processing volume has been reduced and aeration has been increased, but the situation has not improved. What factors can cause abnormal ammonia nitrogen levels? Seeking help
There may be several reasons for the abnormal rise in ammonia nitrogen levels: 1. **Decreased microbial activity**: The relatively high temperature in the O-tank (35–40°C) may have inhibited the activity of nitrifying bacteria. Nitrifying bacteria are more active at lower temperatures (usually 20-30°C). 2. **Increased inflow load or changes in composition**: A sudden increase in the nitrogen content in the inflowing water, or changes in water quality, can cause the processing system’s load to exceed its designed capacity. 3. **Inadequate or uneven aeration**: Even if the aeration volume has been increased, an uneven distribution of the aeration system or existing faults can also lead to insufficient oxygen supply, thereby affecting nitrification. 4. **Inappropriate sludge age or sludge volume**: An appropriate sludge age and volume are crucial for maintaining system stability. Both sludge aging and insufficient quantity can affect the treatment efficiency. To address these issues, the following measures can be considered: – Check and adjust the temperature of Pool O, striving to keep it within the range suitable for nitrate bacteria. - Analyze the influent water quality to understand the sources and concentration changes of nitrogen, and appropriately adjust the pretreatment process. - Inspect and optimize the aeration system to ensure sufficient and uniform oxygen supply. - Conduct regular sludge diagnostics, adjust the amount of sludge returned or discharged, and maintain an appropriate annual sludge volume. It is recommended to combine the above measures, examine and adjust them one by one to achieve the best treatment results. .