Bubbling in aerobic biological tanks is a problem in many wastewater treatment systems. Foam is often sticky, viscous, and colored. It floats and accumulates on tanks, thereby reducing the quality of wastewater and controlling the retention time of sludge.
Foam can also spill into walkways and surrounding areas, causing serious difficulties and operational and environmental risks. So why does foam appear in the sewage system, with BIOFIX find out!
The foam is white
The foam is white and large, rising gradually to the surface of the tank.
- In the early stage of microbiological culture due to load shock, it is necessary to adjust the pump effluent flow.
- The amount of active microorganisms in the treatment tank is too small (less than 10%, equivalent to MLSS <1000mg / liter).
- Due to the high concentration of organic matter in the aerobic biological treatment tank (COD value in the active microbiological tank exceeds the processing capacity of aerobic microorganisms many times (COD> 1200mg / liter).
- The regime of sludge discharge is unreasonable, gradually leading to low concentrations of microorganisms in the tank
How to fix
We check the microbiological concentration in the microbiological tank by measuring SV30, pH, DO. If sludge is still settling normally, students do not increase or decrease it may be because the effluent has many surfactants. At that time, we aerated, stirring for 30 minutes – 1 hour, the foam will gradually reduce then all, usually the pH of wastewater is> 8 =.
If the SV30 is lower than 150, you need to add more microorganisms to the aerobic tank by adding probiotics. In addition, you can reduce the amount of sewage pumped in so that microorganisms can thrive and recover.
The foam is yellow brown
The foam is yellow brown, the foam color resembles the activated sludge at that time. The foam is fragile and contains fine particles of activated sludge, so it does not accumulate seriously in a short time and causes a large amount of waste. There is the appearance of filamentous bacteria.
There are two causes
Due to the fat, grease: the foam is yellowish brown, viscous and they smell bad.
Because microorganisms die: they release strong, foul-smelling substances that form air bubbles on the surface of the water tank. Leading to impurities, dead mud then clinging to air bubbles.
So how to fix it?
Instant: we turn off the air and remove the bubbles.
Strictly control the amount of grease input. Then add probiotics.
Leave to settle for about 1 hour and pump out the waste water. Then pump clean water into Aerotank aeration tank for about 30 minutes and then continue to settle and pump again.
Immediately rescuing the remaining active microorganisms by turning off the aeration to settle for 1 hour, pumping clean wastewater into the Aerotank tank for 30 minutes aeration and letting it settle, continuing to pump out the water.
The foam is gray black
The foam is gray and brittle. The color of bioactive sludge is also gray. Presence of foaming bacteria, low F / M and old mud age.
The reason is that the activated microorganism sludge is inactivated (fine mud) due to malnutrition. Microorganisms lack food, so the microorganism sludge does not grow, the mud is very smooth.
How to fix
Increase the load (amount of food) for microorganisms by
Increase the amount of water to be treated
Adding natural organic substances for growing microorganisms
BIOFIX VIETNAM supplies probiotics directly imported from the US with high microbial density. With a technical team in 5 branch systems, always support customers in the process of microbiological investigation and culture. Contact us for specific advice