In February, the dynamic incentive plan activated sludge operation process failure is an inevitable problem in the operation of activated sludge method, this article sorts out the key points of activated sludge operation 3 questions and 3 answers, the following is presented to you in the form of Q&A exchange examples, hurry up and take a look. Q:1Activated sludge grows rapidly, and the TP in the effluent fluctuates high and low, how to control the amount of sludge?
Answer: 1) Sludge discharge is an important way to remove total phosphorus.
2) The sludge grows too fast, and I think the sludge discharge will also increase. This facilitates the removal of total phosphorus.
3) Anaerobic control is conducive to the effective removal of phosphorus by phosphorus bacteria.
4) The concentration of organic matter in the influent water also has an impact on the effective removal of phosphorus, and the total phosphorus removal rate is low when running at low load and running at high load.
5) For the high and low TP in the effluent, I want to follow up the changes in the phosphorus concentration of the water, the changes in the amount of nutrients, the control of dissolved oxygen, and the sludge discharge mentioned above, you can check it. As long as it's not a major issue in the design, I think the total phosphorus control is controllable.
Q:2The current sludge age is very short, at most four days, which is calculated by the sludge concentration and sludge discharge, not by control! I observed that the biological sedimentation of the aeration tank is very poor, and there are many possibilities of drifting mud on the surface of the secondary sedimentation tank, in short, it is suspended, so our effluent is relatively turbid!
At first, I suspected that the aeration was too large to destroy the flocculation, but our dissolved oxygen was not very high, and it was set at 15mg l, what is the reason, can you help me analyze it?
Answer: 1) I think that whether you are from a professional background or a halfway way home, your understanding of the control parameters of the biological system of wastewater treatment is limited only through textbooks and related tools, and most of the explanations in the books are not clear enough, or the relationship between the parameters is not clear enough. For this reason, as colleagues in wastewater, we should summarize the regulation of various parameters in practice, so that the understanding of practice is clearer.
2) The traditional activated sludge method, the sludge age is 4 days of control, if the inlet water concentration is high, the amount of water is large (i.e., the sludge load is high), there is no big problem, but the sludge load is not high, so the sludge age control is unreasonable.
3) If you have a thorough understanding of the control of each parameter, then whether it is calculated by sludge concentration and sludge discharge volume, or by control! It doesn't matter. However, it is necessary to consider it together with other parameters and summarize the optimal control points in each case.
4) The sedimentation of the aeration tank is poor, according to the parameter of SV30 value, below 30% is normal, otherwise the proliferation of filamentous bacteria should be examined with a microscope.
5) The turbidity of the supernatant is mostly due to the high sludge load, which leads to enhanced biological activity and is not easy to settle. A large number of inactivated sludge protozoa can be observed through microscopy, such as common fast-swimming ciliates such as lateral jumping worms and trichomoniasis. These organisms can directly use free bacteria and organic matter as food sources. At high loads, there is an increase in free bacteria that are not easy to flocculate, providing a large food source for such organisms, which leads to a large number of proliferations. Bacteria that do not flocculate easily and such protozoa cause the activated sludge to settle poorly.
6) There are many reasons for the occurrence of floating mud, and the space is generated** to investigate, is it the bottom of the pool that settles and then floats up, or does it float up before it settles to the bottom of the pool? Color, viscosity, and floating object microscopy are all to be checked. There is no big problem with a small amount of production, and a large amount of production will increase the effluent index and reduce the amount of sludge in the aeration tank.
7) Normal microorganisms are not easy to be broken by aeration, and can quickly flocculate when the water shear force is small.
8) Dissolved oxygen is controlled at 15mg l, is based on cost control, and refers to the dissolved oxygen content of the outlet water of the aeration tank, the aeration at the head of the aeration tank should be tested frequently, must be guaranteed, because, the main position of adsorption oxidation is in the first 2 3 position, the last 1 3 should be prepared for its flocculation, imagine, the outlet is over-aerated, its biological activity is passively increased, how is it conducive to the biological flocculation and sedimentation of the secondary sedimentation tank? Especially when the sludge is aging, the viscosity of the sludge increases, and it is easy to adhere to the small bubbles of aeration and have floating sludge, which is not easy to settle.
Q:3In leather wastewater treatment, how can we effectively control sludge swelling by using the traditional push-flow activated sludge method, and the filamentous bacteria in the activated sludge are overpropagated?
A: In my experience, the production of filamentous bacteria is related to the following:
1) Dissolved oxygen. Dissolved oxygen is too low, below 1 for a long time0 mg l run; Or there is a dead zone for oxygen supply in the biochemical tank.
2) Food-micro-ratio. Usually at low loads (less than 0.).1) It is easy to proliferate filamentous bacteria, especially when there is no anaerobic or anoxic section at the first end.
3) Single inlet water composition. Most of the industrial wastewater inlet water has a single composition, which is not conducive to the growth of normal colloidal bacteria, but is conducive to the proliferation of filamentous bacteria. Filamentous fungi and normal colloidal bacteria are two groups of organisms that require different growth environments.
We should consider the solution from the perspective of whether the operating environment is conducive to mycelonal bacteria. By changing the operation method, it is possible to alleviate the swelling of filamentous bacteria to a certain extent. If treated properly, the filamentous bacteria can disappear.
Methods such as adding inert substances, bleaching powder, raising the pH value, etc., mentioned in other articles, can be tried. However, the key lies in the rationality of the operation method, because when the filamentous bacteria are highly expanded, adding inert substances, bleaching powder, and raising the pH value can have a rapid effect, but the filamentous bacteria are easy to adapt, and after repeated use, they will eventually fail. For highly expansive filamentous bacteria, it is feasible to put some PAC at the outlet of the biochemical tank to improve the sedimentation effect in order to ensure that the effluent meets the standard.
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