What is an appropriate MLSS level in the aerobic tank?
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The COD of the water entering the aerobic tank is around 5500, the SV30 is 80%, and the MLSS is 3800. I was wondering if the MLSS level is too low?
1. Without knowing the water volume, BOD, and tank capacity, it is impossible to determine whether the F/M ratio is overloaded； 2. Based on the data you provided: 1) An SVI value greater than 200 indicates that the sludge has expanded, or that it is fine in texture and has very poor settling properties ； 2) For influent water with a COD of 5500 ppm, the likelihood of filamentous sludge bulking is lower than that of non-filamentous sludge bulking ； 3) Excess organic load causes stress on the system, leading to abnormally high sludge activity and resulting in a large amount of sludge being carried away with the water. This leads to a decrease in sludge concentration, reduced treatment efficiency, and increased oxygen demand ； 4) Insufficient nutrients. Suggestions: 1. Reduce water inflow and increase aeration volume ； 2. Reduce the return flow rate from the secondary sedimentation tank ； 3. Check the nitrogen and phosphorus nutrients; replenish them promptly if they are insufficient.
The water volume is 50 tons per day; the BOD of the raw water is around 3000, and the COD is around 6000. The capacity of the aerobic tank is 800 cubic meters. The aeration rate should be fairly high, with a DO level of around 5-6; urea addition has been stopped over the past month
Oh, no – the capacity of the aerobic tank is 400 cubic meters
There should be an anaerobic stage; if it goes straight to the aerobic phase, sludge bulking is likely to occur, and the sludge concentration is indeed low
With such high COD levels, feeding it directly into the aerobic system – it’s highly unlikely that it will function properly
The process involves UASB followed by anaerobic and aerobic stages; the COD level of the water entering the U-tank is around 6000, and it drops to about 5500 during the aerobic stage
The removal rate by UASB is at least 40% in the worst cases, and can exceed 80% in the best cases. Your anaerobic process isn’t working effectively; the organic load in the aerobic stage is too high. Increase the sludge concentration, and pay attention to the ratio of nitrogen to phosphorus nutrients
I’m really speechless at such a low removal rate for the entire UASB