Sludge poisoning do not be afraid, after reading this article, there are more concerns about the public name: environmental protection water treatment (hbscl01)

<h1 class="pgc-h-arrow-right" data-track="1" > pay more attention to the public name: environmentally friendly water treatment (hbscl01).</h1>

Sludge poisoning is mainly reflected in its suddenness, unpredictability, difficult judgment, and difficult recovery! Therefore, the operation after sludge poisoning is particularly important, this article summarizes the emergency operation steps after sludge poisoning, which can be used as an emergency plan for sewage treatment sludge poisoning!

First, the judgment of the cause of sludge poisoning

After the occurrence of poisoning in the biological treatment system, in order to avoid further expansion of the situation, when we determine whether the biological system is poisoned, we can learn from the hope and hearing of Traditional Chinese medicine, observe its "clinical manifestations" from the three methods of sensory, physical and chemical, and special, and then analyze and judge its "cause".

1. Sensory index analysis

The microbial properties of the biological treatment system are good or bad, which can be shown in the operation of the treatment structures of the sewage treatment plant, the aeration tank and the final sedimentation tank. In the aeration tank, a large number of flocculent sludge positions that can be observed by the naked eye are suspended, called activated sludge flocs. Each floc contains 5,000 active microorganisms. When the operation inspector inspects the scene, he can observe from the "face" of the activated sludge regularly. In the same way as Chinese medicine to see patients, starting with the word "looking and smelling". First of all, the aeration tank is viewed and analyzed from the main items such as color, odor, foam, flow, transparency, etc., that is, it can quickly determine whether the biochemical system is poisoned, which takes the shortest time, which is conducive to management and technical personnel to quickly take countermeasures to avoid further expansion of the situation.

1. Normal state

When the aeration tank is operating normally, the activated sludge is generally yellowish brown with a slight earthy smell. In the process of oxygenation, the normal aeration foam is a small amount of small scattered in the aeration tank, the total area accounts for about 1/10, you can hear the rustling of the aeration tank, the foam is milky white. The liquid level state of the final sedimentation tank is also closely related to the normal operation of the entire system, and attention should be paid to observing the level of the mud surface, the degree of transparency of the supernatant, whether there is drift mud, mud particle size, etc. When the final sedimentation tank is running normally, the supernatant is clear and transparent, and the activated sludge sedimentation properties are good.

2. Poisoned state

At the beginning of microbial poisoning in the biological treatment system, the operator can find that the activated sludge of the aeration tank will generally change sharply from the original yellow-brown to the soil, the foam will be yellow, the individual will increase, and the number will increase, accounting for 30% to 50% of the pool surface; the supernatant of the final sinking pool is turbid, the mud level rises, and a small amount of SS is brought out of the effluent. In the middle and late stages, the operator can find that the activated sludge of the aeration tank will generally change sharply from yellowish brown to black, odorous, and the number of foam will increase sharply, covering more than 90% of the pool surface; there are many water flocs in the final sedimentation tank, the structure of the sludge is loose and the volume is expanded, and there are a large number of mud blocks formed by foam on the surface floating on it, and the sludge settlement performance is very poor.

After receiving the operator's water quality abnormality report, the technician must also compare it with online instrument data such as COD, ammonia nitrogen, and total nitrogen. Generally, after poisoning, the effluent water quality index will change abnormally and show a linear change relationship.

2. Analysis of physical and chemical indicators

After receiving the abnormal situation report of the operation inspector, the management personnel of the sewage treatment plant will generally immediately require the water quality laboratory inspector to conduct laboratory analysis on the frequency of strengthening the water sample and sludge sample of the biological system, take the biological phase observation of the activated sludge, monitor the oxygen consumption rate of the activated sludge, DO, sludge sedimentation ratio, sludge volume index and density index, sludge sedimentation rate and other measures for further physical and chemical analysis, which can roughly determine whether the microorganisms in the biological system are poisoned, the degree of poisoning, and the change process of microorganisms in the activated sludge.

Although this analysis takes a long time, generally 2 to 3 h, the reliability of the data is high, and the degree of wastewater purification and the state of activated sludge are generally judged by the multi-energy, which is often used as the basis for emergency regulation of the biochemical system of the sewage treatment plant.

3. Special analysis of heavy metal indicators

Heavy metal analysis instruments are more expensive, and general sewage treatment plants are not configured. Sewage treatment plants can take sewage and sludge samples when necessary and send them to the National Standardization Laboratory (Urban Drainage Monitoring Station) for special analysis of heavy metal indicators, similar to the special examination of special patients in large hospitals by doctors in general hospitals, and the final data is obtained to confirm the true reliability of the above sensory examination and physical and chemical analysis results. After the sewage treatment plant is poisoned by microorganisms in the biological system, the water samples and mud samples can obtain accurate data after special analysis of heavy metals.

This process generally takes the longest time, 1 to 2 d, but the data is the most accurate, in order to confirm whether the biochemical system is poisoned, mainly what kind of heavy metals enter, how much the specific amount, to what extent, but also to confirm the accuracy of the above two steps of analysis. Usually, this type of monitoring data is reported by the sewage treatment plant as the basis for biochemical system poisoning to the superior authorities and environmental protection supervision departments.

2. Countermeasures

After the symptoms of poisoning occur in the biological treatment system, first of all, through phenomenon observation and physical and chemical analysis, it should be determined that the cause of poisoning is caused by excessive heavy metals in the water, and the symptoms should be prescribed, and the emergency plan should be quickly activated, and effective control measures should be taken to prevent the situation from further expanding. Sewage treatment plants generally respond to them by taking two measures, external and internal, as follows.

1. External measures

1. Report abnormal water quality to the superior

After the sewage treatment plant finds that the water ingress is abnormal, it starts the emergency plan for abnormal water quality, and immediately reports the relevant situation to the superior competent department and the environmental protection department of the jurisdiction.

2. Investigation of pollution sources in the jurisdiction

After the sewage treatment plant reports the abnormal water quality to the superior, it should immediately arrange personnel to leave samples of the inlet water of the pumping station outside the plant and the inlet and outlet water of the plant for 24 hours. Organize pipeline personnel to sample the sewage of the pipe network outside the factory for many times, and according to the characteristics of abnormal water inflow, the pollution sources in the jurisdiction, especially the sewage of large polluting enterprises, are focused on investigation and sampling to determine the specific pollution sources, grasp the first-hand information, and provide a basis for the production regulation and control in the factory.

3. Cooperate with the inspection of the Environmental Protection Bureau

Sewage treatment plants should actively seek the support of the environmental protection bureau of the jurisdiction, and provide strength to cooperate with them to carry out supervision and inspection work, stop the excessive discharge of pollutants by enterprises, and restore the water inflow of the sewage treatment plant to normal in the shortest possible time, meet the relevant standards, and lay a good foundation for the internal process regulation of the sewage treatment plant.

2. Internal measures

While taking external measures, the sewage treatment plant should start the corresponding emergency plan according to the abnormal quality of the inlet water, and carry out targeted adjustment and control of the sewage biological treatment process to prevent the situation from further expanding.

1. Adjustment of water intake

After the occurrence of abnormal water inlet events, control the inlet water of the inlet pump room, use less water inlet or intermittent water intake according to the degree of abnormality, and minimize the amount of water inlet under the condition of ensuring that the pipeline sewage does not overflow, so as to prevent high concentrations of toxic and harmful pollutants from further poisoning microorganisms in the biochemical system and prolong the recovery process of the biological system.

2. Increase the frequency of water quality testing

After the occurrence of abnormal water inlet events, the frequency of water quality tests should be increased from the original 1 time per day to 2 to 3 times, the observation of the biological phase of the aeration tank should be strengthened, and more water quality data of the whole process should be provided, so as to facilitate the adoption of more scientific process control measures. In the water quality test, attention should be paid to the observation of changes in protozoa such as amoeba, marsula, and rotifers in animals that indicate activated sludge poisoning and disintegration, as well as rotifers and coelent rotifers in animals, as well as protozoa such as reedia, bell worms, monototopods, and linguides that indicate normal and good organisms of activated sludge.

3. Reduce reflux and increase sludge discharge

After the occurrence of abnormal water inlet events, while reducing the amount of water inlet, the sludge return flow should be reduced, the discharge time of the inert sludge of the final sedimentation tank should be increased, the poisoned sludge that has been retained in the final sedimentation tank should be further reduced and returned to the aeration tank, the sludge concentration of the aeration tank should be appropriately reduced, the polluting substances in the sewage should be separated or discharged, the sludge expansion and sludge floating should be controlled, and the poisoning hazard should be controlled to a minimum.

4. Domestication and cultivation of activated sludge microorganisms

After the implementation of the above measures, if the degree of poisoning is not deep, the aeration tank can be controlled by intermittent water inlet and intermittent aeration, and the aerobic tank DO can be maintained at 2 to 3 mg/l to accelerate the growth of activated sludge microorganisms. After the microorganisms form a more obvious activated sludge floc, the operation mode of the aeration tank can be operated by continuous water inlet and continuous aeration, the number of open units of the blower can be changed, so that the aerobic tank DO continues to remain at 2~ 3 mg / l, increase the return flow and reduce the amount of sludge discharge, which can increase the aeration tank MLSS to 2500 ~ 3500 mg / l, and the mixture SVI to 60 ~ 100 mg / l. If a large number of protozoa (such as bell worms) and a small number of metaphytes (such as rotifers) are observed in the biological phase, it means that the domestication and cultivation of activated sludge is basically successful, and the biochemical system has returned to normal.

5. Add the same type of sludge

If the degree of poisoning is deep, part of the activated sludge can be pumped from the nearest activated sludge sewage treatment plant and introduced in the aeration tank to accelerate the recovery of the biochemical treatment system of the plant. After the microorganisms have recovered and the water quality characterization has recovered, the water inlet is gradually turned on, the water is slowly fed, and the sampling analysis and monitoring are continued after the environmental protection department feedback the pollution source. Normal operation resumes after the microbial system returns to normal and the water quality characterization returns.

6. Summarize experience

After the situation is controlled and the emergency task is completed, the sewage treatment plant should summarize the accident in time, analyze the cause of the accident, and compile the accident analysis report, find the weak links and improve them, and prevent the recurrence of similar incidents.

7. Preventive measures

Although sludge poisoning in sewage treatment plants is relatively rare, it should attract the attention of sewage treatment plant management, technicians and operators because of its suddenness and high degree of harm and its difficulty of detection. Such accident plans should be regularly rehearsed to familiarize all personnel with response measures