1、 What is the appropriate level of dissolved oxygen control for the filter?
The DO of denitrification deep bed filter should generally be controlled below 0.5mg/L, the lower the better.
2、 Two stage cascade biological filter, first dn and then cn; if the influent ammonia nitrogen of cn tank is between 2-5, the total nitrogen is approximately 8-9; The total nitrogen in the effluent of the filter should be controlled below 12 and the ammonia nitrogen should be below 0.8; What is the reasonable range for CN pool do control?
If in order to remove ammonia nitrogen, the dissolved oxygen should be higher, at least 2-3mg/L or above, and attention should be paid to the COD of the influent not being too high, otherwise the ammonia nitrogen cannot be reduced.
3、 The upgrading and renovation have been basically completed. We have adopted the AAO BAF deep treatment system technology and added two sets of denitrification filters. After adding denitrification filters, the pH has increased to 8.3 and 8.4; There is no carbon source added yet, and the total phosphorus treatment effect is not ideal. Is there any good solution? (After adding PAC, the addition of soda ash was stopped for a period of time)
Denitrification filters contribute alkalinity, which is not a problem. Phosphorus removal is not carried out on denitrification filters. You need to determine whether biological phosphorus removal or chemical phosphorus removal is the main method based on the experimental conditions on site.
4、 In the recent rainstorm, the influent concentration is low and the COD50 is about 50. Now the total phosphorus in the effluent is high. Is it due to the lack of carbon sources in the anaerobic section and poor anaerobic phosphorus release? Is it necessary to add carbon sources in the anaerobic section because we are MBR membranes? Is there no other way to add phosphorus removal agents?
The control of biological phosphorus removal is relatively difficult to control, and the carbon source added also needs to use acetic acid. For short-term water inflow effects, it is recommended to use chemical phosphorus removal agents to quickly remove them. MBR membrane is difficult to have a good anaerobic environment due to the continuous aeration of the membrane scrubbing fan, so chemical phosphorus removal using phosphorus removal agents is better.
5、 Due to the inflow of river water, the total phosphorus is only about 1. Does the dosage of phosphorus removal agent increase instead of decrease?
Due to low influent concentration, the effectiveness of biological phosphorus removal decreases, resulting in an increase in chemical phosphorus removal agents.
6、 What are the possible causes of high effluent COD? Previously normal, there was a sudden increase in water output.
It depends on the changes in your other indicators. Activated sludge may be impacted, with insufficient dissolved oxygen, sudden changes in inlet water quality, excessive sludge discharge, and sludge aging.
7、 Does the effluent ammonia nitrogen remain unchanged or very low, while COD increases?
That may be due to the aging of sludge, an increase in suspended solids in the effluent, and the lack of filtration in COD treatment, which will cause suspended solids in the effluent to increase COD.
8、 What should we do with the long floating duckweed in the regulating pool?
1. Concentrate on salvaging floating duckweed on the water surface, increase aeration, and try to avoid anaerobic conditions underwater; (Timely detection and handling)
2. Duckweed is often related to the ratio of nitrogen and phosphorus elements in water. According to the inflow situation, measures such as adding chemicals should be taken to adjust the nitrogen phosphorus ratio;
3. Appropriately increase the sludge discharge volume, and if the water volume allows, increase the clarified reflux;
4. Improving the process and adding activated carbon can effectively control nitrogen and phosphorus in water.
