How to remove biological foam quickly
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Recently, it was found that in the CASS tank (closed type), there is a large amount of foam about 20 centimeters thick, both during aeration and when the tank is at rest; this foam is presumed to be biological foam. Usually, only a small amount of used diesel is added to the tank. It is understood that defoamers can also be added; I wonder if this will have an impact on the activated sludge in the biological tank and on the effluent? What causes excessive foam, and are there any better methods? Could an experienced expert give some guidance?
Using a small amount of defoamer should be fine, but the cause needs to be identified. Determine whether the incoming water contains dishwashing liquid or laundry detergent, and whether the age of the biochemical sludge is too long or too short.
Excessive foam is mainly due to the high concentration of surfactants in the wastewater. The use of defoamers and used diesel can have an impact on water quality and activated sludge, and both the addition of used diesel and defoamers can affect the quality of the effluent. Factors that can cause foam include changes in temperature, growth of filamentous bacteria, pH levels, and low dissolved oxygen levels. ； It is recommended to add spray pipes around the CASS tank; spraying water can provide some relief, and an appropriate amount of foam has little impact on the treatment efficiency.
There is no dish soap or similar in the raw water, and the sedimentation ratio is around 30%
It’s the same CASS pool, and the same issue – it seems there are very few answers related to CASS pools. I’m not sure if this is because it’s not widely used. I’m also seeking help; if you can find out the reason, please share it. Thank you
In my opinion, there’s no need to rush when encountering a bubble. There are more than surfactants as the cause of foam. High loads, filaments, and the like can all cause foam. It is necessary to analyze based on the specific circumstances on site.
My personal analysis suggests that this is likely the main reason