1. What are the abnormal phenomena in the aerobic tank?
① Aerobic sludge is black or white (low or high dissolved oxygen)
② The supernatant of aerobic tank is turbid (poor sludge adsorption performance or too high dissolved oxygen leads to sludge disintegration, and too low dissolved oxygen cannot oxidize organic matter).
③ The sludge foam returned from the secondary sedimentation tank becomes sticky (the sludge stays in the secondary sedimentation tank for too long, and the activity becomes worse after denitrification).
④ The increase of foam in aerobic pool (whether it is caused by the change of sludge itself or by substances added in production, can be judged by the color and viscosity of foam).
⑤ The removal rate of aerobic tank decreased (specific reasons: sludge activity, sludge load, dissolved oxygen, sludge concentration, water temperature, etc.). )
⑥ Sludge bulking in aerobic tank (controlled by increasing sludge discharge and adjusting nutrient addition, so as to stabilize water inflow and ensure sufficient dissolved oxygen and suitable water temperature).
⑦ When aerobic sludge settles, the supernatant is turbid and fine (sludge overload or sludge disintegration, loose sludge structure and thin bacterial micelle).
⑧ There are fewer aerobic microorganisms, loose structure and thin bacterial micelles (too low or too high load, insufficient dissolved oxygen, sludge bulking and insufficient nutrients).
Pet-name ruby aerobic pool dissolved oxygen is high for a long time, but the effluent is turbid and COD is high (sludge load is low for a long time, sludge disintegrates, bacterial micelle oxidizes, and oxygen is not consumed).
Attending sludge aging (the reasons leading to sludge aging are long sludge age and low load. This leads to poor emissions, more fine sludge and rotifers, and increased oxygen consumption)
2. What abnormal phenomena will occur in the secondary sedimentation tank?
(1) scum floating mud (sludge aging or short sludge age, sludge staying in the secondary sedimentation tank for too long)
② The effluent is turbid, with high COD and peculiar smell (insufficient dissolved oxygen in aerobic tank and short retention time in aerobic tank).
③ The effluent is turbid, the COD is not very high, and there are many fine sludge (the aerobic tank has sufficient dissolved oxygen, the sludge load is small, and the sludge is aging).
④ The effluent is turbid, with high COD and more fine sludge (insufficient dissolved oxygen in aerobic tank, aging sludge and heavy sludge load).
⑤ Remove high COD effluent (sludge bulking in aerobic tank)
⑥ Fine mud tumbling (there is something wrong with the sludge in the aerobic pond, so it is suggested to increase nutrients and adjust the appropriate sludge age).
⑦ The sludge layer in the secondary sedimentation tank is too high (sludge bulking or reflux ratio in the aerobic tank is small).
⑧ Bubbles appear on the surface of the secondary sedimentation tank (sludge stays in the secondary sedimentation tank for too long).
Pet-name ruby reflux sludge black smelly sticky (sludge retention time is too long, reflux ratio is small)
Attending the effluent color becomes darker (the physicochemical effect becomes worse, the effect of anaerobic tank becomes worse or the sludge in aerobic tank expands).
3. Why is the supernatant clear but the COD is high when sludge bulking occurs in aerobic pond sludge?
① Filamentous bacteria have strong adsorption, and a large number of filamentous bacteria have net catching effect, so the supernatant is clear.
(2) A large number of filamentous bacteria extend out of the micelle, so that the micelle can't get enough oxygen and can't oxidize organic matter into inorganic matter.
(3) The bacterial micelle can't get enough oxygen, and its reproductive activity decreases, and the bacterial micelle becomes thinner and its activity decreases.
4. What is the reason for the turbidity of anaerobic pond effluent?
① The sludge load of anaerobic tank is too high.
② There are many suspended substances in the effluent of the primary sedimentation tank.
③ The sludge concentration in the anaerobic tank is too high.
④ The nutrients in the anaerobic tank are unbalanced.
⑤ The influent temperature of anaerobic tank is too high.
5. What is the reason for the rolling turbidity of fine sludge in the secondary sedimentation tank?
① The sludge load in the aerobic tank is too small, the aeration rate is too high, and the sludge itself is oxidized, resulting in poor flocculation effect and scattered sludge structure (turbid water and more suspended matter).
② The sludge load in aerobic tank is too large, the dissolved oxygen is insufficient, the adsorption performance of sludge becomes worse, and the organic matter cannot be completely decomposed.
(3) The load of the secondary sedimentation tank is too high, or gravity flow occurs due to uneven water distribution in the secondary sedimentation tank, and the local flow rate is too fast to pick up sludge.
④ The reflux ratio of the secondary sedimentation tank is too large, the mud layer of the secondary sedimentation tank is too low, and the mud layer stirred by water flow is too large (this reason accounts for less).
⑤ Too much sludge is discharged from the aerobic tank, which leads to short sludge age, and the newly synthesized sludge flocs are difficult to settle (there are many suspended solids in the water).
⑥ The sludge in aerobic tank is too old and aging.
⑦ The sludge in aerobic pond has insufficient nutrients or unbalanced nutrient ratio (too high ratio of nitrogen to phosphorus).
⑧ Sludge bulking occurs in the sludge in the aerobic tank, which leads to poor sedimentation. When the sludge layer in the secondary sedimentation tank is high, the sludge will be carried away by the water flow (this will happen if the SVI value is too high or too low).
Pet-name ruby aerobic pool sewage ammonia nitrogen content is high.
6. What are the reasons for the scum and sludge in the secondary sedimentation tank?
① The reflux ratio of the secondary sedimentation tank is small and the sludge retention time is too long. After anaerobic denitrification, sludge is carried away by gas.
(2) A large amount of physical and chemical sludge and anaerobic sludge enter the aerobic tank, some of which cannot be converted into aerobic sludge and become a scum discharge system.
(3) Sludge deterioration in aerobic tank.
(4) There are many foams in the aerobic tank, which float to the secondary sedimentation tank after mixing with sludge/suspended matter.
⑤ The aerobic tank has low sludge concentration (high sludge load) or high dissolved oxygen (possible).
⑥ The sludge in aerobic tank is aging or too short, and the flocculation, COD removal rate and treatment effect are poor.
7. What is the reason of insufficient dissolved oxygen in aerobic tank?
① Due to the aging of sludge, the concentration of sludge in aerobic tank rises rapidly or the oxygen consumption increases.
(2) There are a lot of suspended solids in the effluent of anaerobic tank, which consumes a lot of dissolved oxygen after entering aerobic tank.
(3) The blower can't stop running or the blower pressure is not enough (this rarely happens).
(4) The COD in the effluent of the anaerobic tank suddenly increases a lot, or the influent suddenly increases, resulting in a large impact load, which leads to a large load in the aerobic tank.
⑤ The aeration head is seriously damaged or blocked, and there are many bubbles in the aerobic tank.
8. What is the cause of sludge bulking in aerobic tank?
① The dissolved oxygen in aerobic pool is low or high for a long time (possible).
② The sulfide content in raw water or anaerobic effluent is too high, which leads to the proliferation of sulfur bacteria.
③ The load of aerobic pool is low or high for a long time.
④ The water temperature in aerobic pool is high.
⑤ Unbalanced nutrients or lack of nutrients (low nitrogen and phosphorus content).
⑥ pH value of influent.
⑦ The sludge in aerobic tank is too old, and the increase of oxygen consumption leads to insufficient dissolved oxygen.
9. What is the reason for the disintegration of sludge in aerobic tank and excessive fine sludge in supernatant?
① The aerobic tank has small sludge load, excessive aeration, self-oxidation of sludge, poor flocculation and loose sludge structure (clear, with more fine sludge and low COD).
② The sludge load in the aerobic tank is too large, the sludge adsorption performance becomes worse, the organic matter can not be completely decomposed, and the sludge structure is scattered (turbid, opaque and high COD) by microscopic examination.
(3) Excessive sludge discharge from aerobic tank leads to short sludge age (SVI value is 70~ 120, and there is less fine sludge in secondary sedimentation tank within this range).
④ The influent of aerobic pond contains toxic substances or the sludge is aging, and the sludge is long (turbid, fine, with high COD and a large number of rotifers under the microscope).
⑤ The nutrient in aerobic pool is insufficient or the nutrient ratio is unbalanced (N and P are low).
10. Why are there many bubbles in the aerobic pool?
① Raw water contains a lot of surfactant components (substances added in the production process make the foam white, and the bubbles are delicate, light and non-sticky).
(2) Micro bubbles generated after newly installing aeration head (short-term impact)
(3) A large number of lipid substances or microorganisms are produced in the process of microbial reproduction (due to the growth and reproduction activities of microorganisms themselves, the foam is turbid, the bubbles are large and sticky).
(4) Sludge denitrification foam (the foam produced by denitrification after aerobic sludge stays in the secondary sedimentation tank for too long).
1 1. Why is the COD removal rate in aerobic tank low?
(1) The sludge in the aerobic tank is aging and the sludge age is long.
② The aerobic tank has high sludge load, short sludge age, large reflux and short residence time.
③ The aerobic tank has low sludge load, and long-term high dissolved oxygen leads to sludge autooxidation (low removal rate and high dissolved oxygen), with more fine sludge and less activated sludge.
④ Lack of dissolved oxygen in aerobic pool.
⑤ Insufficient nutrients or unbalanced nutrient ratio (too high ratio of nitrogen and phosphorus)
⑥ The removal rate of COD in anaerobic tank is low, the anaerobic hydrolysis effect is poor, and the effluent COD concentration is too high.
All landowners raw water contains toxic substances, sludge poisoning.
⑧ The accumulated value of inorganic salts exceeds the specified range.
Pet-name ruby aerobic pool impact load is big or aerobic pool sludge bulking phenomenon.
12. Why is the removal rate of COD in anaerobic tank low?
① Insufficient sludge concentration in anaerobic tank (biochemical sludge flows back to anaerobic tank)
② A large amount of physicochemical sludge (mostly inorganic) enters the anaerobic tank.
(3) The anaerobic pool is undernourished or the proportion of nutrition is unbalanced.
④ The water temperature exceeds the adaptive range of anaerobic microorganisms (above 40℃).
⑤ The influent pH is higher than 10.5 or lower than 6.5.
⑥ The retention time of anaerobic tank is too short to reach anaerobic hydrolysis state (design problem).
⑦ Import toxic substances.
13. What is the reason why there is a lot of fine sludge in the supernatant of aerobic tank and it is difficult to settle after tumbling?
(1) The sludge in aerobic pond is deficient in nutrients or the proportion of nutrients is unbalanced.
② The sludge load in the aerobic tank is too high (the effluent from the secondary sedimentation tank is turbid with high COD, and the supernatant after sludge precipitation in the aerobic tank is subdivided and turbid)
③ The sludge load in aerobic tank is too low, aeration is too high, and sludge itself is oxidized to produce fine sludge (the removal rate of COD in aerobic tank is low, and the effluent COD is high).
④ Low sludge load, long sludge retention time and excessive aeration in aerobic tank lead to poor sludge flocculation effect (loose sludge structure, but high or not low COD removal rate).
14. How to solve the problem of suspended solids (sludge) in the pulse effluent of anaerobic tank?
① Control the physicochemical sludge in the primary sedimentation tank to enter the anaerobic tank (necessary).
② Siphon sludge discharge pipe is added at the top of anaerobic tank (sludge discharge at the bottom of anaerobic tank is not recommended).
(3) adding polypropylene or polyaluminum to the anaerobic tank (4) reducing water inflow or discharging sludge at the bottom of the anaerobic tank.
15. How to solve the problem of sludge bulking in aerobic tank?
① firstly, increase the sludge discharge to solve the problem of poor sedimentation effect, and then increase the sludge concentration after improvement to reduce the sludge load.
(2) Increase the sludge discharge from aerobic tank and reduce the sludge age (it should last for about two months in severe cases)
(3) Control the water temperature within a suitable range, stabilize the water inflow, and keep sufficient dissolved oxygen in the aerobic tank (necessary).
(4) Increase the addition of nutrients in the aerobic tank.
⑤ If the mud layer of the secondary sedimentation tank is high, the reflux flow can be increased, the water inflow of each secondary sedimentation tank can be adjusted, or polypropylene can be added (temporary control measures).
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