Analysis of Common Problems in Aerobic Tank
QUESTION:
Sludge bulking in aerobic tank
ANSWER:
1. The dissolved oxygen in the aerobic tank may be low or high for a long time
2. The sulfide content in raw water or anaerobic effluent is too high, leading to a large number of sulfur bacteria
3. The load of aerobic tank is low or high for a long time
4. The water temperature in the aerobic tank is too high
5. Nutrient materials are unbalanced or lack nutrient N and P
6. PH value of influent water
7.Excessive sludge age in aerobic tank leads to insufficient dissolved oxygen due to increased oxygen consumption
QUESTION:
Sludge disintegration and fine crushing of supernatant in aerobic tank
ANSWER:
1. Aerobic tank sludge load is small, aeration is excessive, sludge is self oxidized, sludge flocculation is poor, sludge structure is loose, clear, fine sludge, multi COD is not high
2. The sludge load in the aerobic tank is too large, the sludge adsorption performance becomes poor, and the organics cannot be completely decomposed. The microscopic examination shows that the sludge structure is turbid, opaque, and high COD
3. Excessive sludge discharge in aerobic tank leads to short sludge age in aerobic tank. SVI value is 70120, which is suitable for this range. There is less fine sludge in secondary sedimentation tank
4. The influent of the aerobic tank contains toxic substances or the sludge is aged and muddy, and there are many rotifers with fine sludge and high COD
5. The nutrient material in the aerobic tank is insufficient or the proportion of nutrient material N and P is unbalanced
QUESTION:
Large number of foam in aerobic tank
ANSWER:
1. The raw water contains a large amount of surfactant ingredients. The foam added in the production process is white, small, light and without viscosity
2. Short term impact of tiny bubbles generated after new installation of aerator
3. A large amount of lipid substances are produced during microbial reproduction or the foam from microbial growth and reproduction activities is muddy bubble with large viscosity
4. Sludge denitrification foam aerobic sludge stays in the secondary sedimentation tank for too long, and the foam produced after denitrification has a viscous mud color
QUESTION:
Low COD removal rate in aerobic tank
ANSWER:
1. Aging sludge in aerobic tank
2. High sludge load, short sludge age, large return flow, and short retention time in aerobic tank
3. Low sludge load in aerobic tank, high dissolved oxygen for a long time, resulting in low sludge self oxidation removal rate, high dissolved oxygen, more finely crushed sludge, less activated sludge
4. Insufficient dissolved oxygen in aerobic tank
5. Nutrients are insufficient or the proportion of N and P is unbalanced
6. Low COD removal rate in anaerobic tank, poor anaerobic hydrolysis effect, high COD concentration in effluent
7. Raw water contains toxic substances and sludge poisoning
8. The cumulative value of inorganic salt exceeds the specified range
9. The impact load of the aerobic tank is large or sludge bulking occurs in the aerobic tank
QUESTION:
The fine sludge in the supernatant of aerobic tank is too much and the fine sludge is difficult to tumble and settle
ANSWER:
1. The nutrient material of aerobic sludge is insufficient or unbalanced
2. The sludge load of aerobic tank is too high. The effluent of secondary sedimentation tank is turbid. COD is high. The sludge in aerobic tank is turbid after sedimentation
3. The sludge load in the aerobic tank is too low, the aeration is excessive, and the fine sludge produced after the sludge self oxidation is excessive. The COD removal rate in the aerobic tank is low, and the COD in the effluent is high
4. The sludge load in the aerobic tank is too low, and the sludge retention time is too long, which leads to poor sludge flocculation. The sludge structure is loose, but the COD removal rate is high or not low
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