1. Chemical foam
Active agent foam: When there are surfactants or other foaming substances such as detergents and colloidal organic substances in the sewage, a large amount of small and light white brown unstable foams will appear on the water surface under the conditions of water flow speed, drop, aeration, and blowing off. This kind of wastewater belongs to polymer synthetic materials and has poor biodegradability, which is a difficult problem in sewage treatment.
Oily and suspended foam: This is a physicochemical foam produced by the action of tiny bubbles of high SS and high oily waste water.
Treatment method: This type of foam can be coagulated by adding ferric sulfate or the like in the pretreatment of sewage, adsorbing the surfactant and changing the hydrophilicity of the surfactant, and then performing catalytic oxidation treatment such as Fenton or enhanced oxidant. The macromolecule is oxidized to a small molecule or carbon dioxide and water, and then diluted to adjust to biochemical treatment.
2. Biological foam
Biofoam is generally brown or taupe. There are many reasons for this type of foam. Such as the brown foam caused by too low dissolved gas in thecommon biochemical pool, and taupe foam caused by too low MLSS or microbial abnormalities. Filamentous bacteria grow abnormally and accumulate with bubbles and floc particles. This foam is relatively difficult to handle.
Treatment: This type of foam can be treated by adjusting DO and MLSS in water, sludge reflux and other methods. Or it can be treated by adjusting the balance by adding nutrient bacteria to increse the DO concentration.
Post time: Aug-15-2019