How to deal with sludge deflocculation during long-term operation at low load?
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The A/O contact oxidation process is being used. Given the above situation, I hope experts can help resolve it. Thank you
This is an interesting question, but could the original poster provide more details? For example, what kind of water is being treated, what are the quality parameters, the temperature, and what are the treatment processes? I think everyone will be interested in participating in the discussion
The wastewater to be treated is glyphosate-containing wastewater, and the treatment process used is contact oxidation at a temperature of around 30 degrees
It is recommended to increase the sludge recirculation rate, reduce the cycle time, and raise the sludge concentration
If the amount of wastewater to be treated or its concentration remains low for an extended period while the aeration volume stays at normal levels, over-aeration occurs, which leads to the oxidation of the sludge itself, a decrease in the flocculation capacity of the microbial flocs, and ultimately results in the breakdown of the sludge.
If the amount of wastewater to be treated or its concentration remains low for an extended period while the aeration volume stays at normal levels, over-aeration occurs, which leads to the oxidation of the sludge itself, a decrease in the flocculation capacity of the microbial flocs, and ultimately results in the breakdown of the sludge. The solution is to reduce the number of fans in operation or the number of aeration tanks in use, by operating only some of the aeration tanks.
I’m not sure whether by low load the poster is referring to a low sludge load or a lower overall water inflow volume (i.e., a low operational load). If it’s the former, could considering reducing the sludge concentration be an option, given that the quality of the raw water remains relatively stable? If it’s the latter, could we consider shutting down some of the equipment? (Of course, this must not be done if the water supply is unstable, especially regarding the biochemical processes!) ! !
At low load levels, since the microorganisms do not have enough food, they end up consuming their own nutrients, which leads to the formation of aged sludge. This makes it easier for the microbial flocs to disintegrate. The sludge concentration can be reduced by removing sludge. Additionally, high dissolved oxygen levels can occur in such conditions, so it is necessary to reduce the amount of oxygen supplied.
Is long-term operation at low load carried out in accordance with the design specifications? Sometimes, chemical wastewater is designed to be treated at a low load in order to meet the requirements for effective treatment, and it is thus designed with a low load. If sludge disintegration occurs at low load levels in the design, it may be due to sludge poisoning, and it is necessary to analyze the influent water for the presence of harmful substances. If low-load operation is caused by the water inflow not meeting the design requirements, it is due to too slow microbial proliferation, which fails to meet the demands of microbial metabolism; this leads to the auto-oxidative decomposition of the biofilm, causing it to become loose and disintegrate.