Family, we're in big trouble! Just finished adding mud, but the amount of water entering slowly drops, causing the dissolved oxygen in the aerobic tank to skyrocket to the "explosive" level. What's going on? Don't panic, let's analyze and solve it step by step. I have gathered all the practical experience I have accumulated over the years, and I'm sure I can help you grasp the problem!
Firstly, we need to understand why this situation has occurred. When we first added the mud, the microorganisms had not yet adapted to the new environment, just like we need to take a break when we arrive in a strange place. At this point, the inflow suddenly decreases, and the rate at which microorganisms consume oxygen slows down. However, the aeration equipment continues to supply oxygen at its original pace, causing dissolved oxygen to rise rapidly! Moreover, the newly added mud has unstable activity and an abnormal demand for oxygen, which exacerbates the problem of excessive dissolved oxygen.
It's not a small matter that the dissolved oxygen is too high! For microorganisms, it's like when we suddenly reach a place with extremely high oxygen concentration, we can become intoxicated with oxygen and become dizzy and disoriented. Excessive dissolved oxygen can damage the cell membrane of microorganisms, affecting their normal metabolism and leading to a decrease in activity. And it may also spoil the aerobic bacteria that were originally the "main force" in treating sewage, making them delicate and prone to strike once the environment changes slightly. In addition, from a cost perspective, high dissolved oxygen means that the aeration equipment has been operating at high loads, causing electricity bills to rise rapidly, making it a "big spender"!
So how should we handle it? Don't worry, I have compiled a few super practical methods for everyone!
It's like turning on the air conditioning too hard at home, let's first raise the temperature a bit. You can try reducing the air supply of the aeration equipment, such as adjusting the air volume knob of the blower or adjusting the number of aeration heads turned on. But when adjusting, you can't be too aggressive. You have to take it slowly and measure the dissolved oxygen value every 15 to 20 minutes to see the effect after adjustment. If you find that the decrease in dissolved oxygen is too slow, slightly increase the adjustment range. If you are using an intelligent aeration system, it is even more convenient. You can directly set the target dissolved oxygen value on the operation panel and let the system adjust automatically.
Step two, find a way to increase the water intake
Since the current inflow is low, find a way to increase it! First, check the inlet pipe to see if there is any blockage, such as debris or silt accumulation. If there is, arrange for someone to clean it up quickly. If there is no problem with the pipeline, communicate with the upstream process to see if it is possible to coordinate and increase the amount of sewage transported. If it is really impossible to increase the amount of sewage, you can also add some clean water to the aerobic tank to dilute the mixture in the tank, so that the speed of oxygen consumption by microorganisms will be relatively faster. However, adding too much clean water is not advisable, as it may damage the living environment of microorganisms. Generally, it is appropriate to control it at around 5-10% of the aerobic tank volume.
Step three, adjust the sludge concentration
The newly added mud may have too much energy, leading to an imbalance between the supply and demand of microorganisms and oxygen. We can appropriately discharge a portion of the sludge to reduce its concentration. But the sludge cannot be discharged randomly, and it needs to be operated according to indicators such as sludge settling ratio (SV30) and sludge concentration (MLSS). Generally speaking, it is more appropriate to control SV30 at 20% -30% and MLSS at around 2000-4000mg/L. When discharging sludge, slowly discharge from the bottom of the aerobic tank, observe the state of the sludge and changes in dissolved oxygen while discharging. Once the appropriate value is reached, stop discharging immediately.
Step four, add fuel to microorganisms
As mentioned earlier, the newly added mud has unstable activity. We can add some nutrients, such as nitrogen and phosphorus sources, to ensure that the microorganisms can eat enough and recover their vitality as soon as possible. Generally added in a ratio of BOD5: N: P=100:5:1. Nitrogen source can be supplemented with urea, and phosphorus source can be supplemented with potassium dihydrogen phosphate. When adding, dissolve these nutrients in water first, and then slowly and evenly add them to the aerobic tank. Do not pour them all at once, otherwise microorganisms may have "indigestion".
Step five, continuous monitoring and adjustment
Dealing with these issues is not the end, we need to constantly monitor the various indicators of the aerobic tank. Measure dissolved oxygen, pH value, sludge concentration and other data every 1-2 hours to observe the state of microorganisms, such as using a microscope to see if there are any changes in the morphology and quantity of microorganisms. If dissolved oxygen begins to rise again or other indicators are abnormal, it is necessary to analyze the cause in a timely manner and adjust the treatment measures again.
Finally, let me remind everyone that when dealing with the issue of high dissolved oxygen, one must be patient and not rush. Each adjustment measure may take some time to see significant results, and the situation of different sewage treatment plants is also different, so the methods need to be flexibly adjusted according to the actual situation. As long as we follow these steps step by step, we can definitely reduce the dissolved oxygen in the aerobic tank and put the sewage treatment system back on track! I hope these experiences can be helpful to everyone. If you have any further questions, feel free to communicate anytime!
