Why-Does-Dissolved-Air-Flotation-System-Perform-Poorly-in-Some-Industrial-Wastewater-Applications

Dissolved air flotation is widely used in industrial wastewater treatment for removing oil, grease, and fine suspended solids. However, some industrial clients report unstable performance or low removal efficiency. Understanding the reasons behind this issue is important for proper system design.

One of the most common reasons is improper wastewater characteristics. DAF systems are designed for light particles and emulsified oil, not heavy solids. If wastewater contains high-density suspended solids, sedimentation or lamella clarifiers may perform better.

Another key factor is chemical dosing. DAF systems rely heavily on coagulation and flocculation to form particles large enough for bubble attachment. Incorrect chemical dosage can lead to weak flocs or excessive chemical consumption, both affecting performance.

Air saturation efficiency also plays a critical role. If the dissolved air system is not properly maintained, microbubble generation will be insufficient, reducing flotation efficiency.

Hydraulic overload is another common problem. When flow rate exceeds design capacity, separation time becomes insufficient, leading to poor effluent quality.

In some industries such as petrochemical wastewater treatment, emulsified oil is difficult to separate without pre-treatment. In such cases, CPI oil separators or chemical breaking systems are required before DAF.

Sludge handling system performance also affects overall operation. Poor skimming or sludge removal can lead to re-entrainment of solids.

Regular maintenance is necessary, including checking recycle pumps, air saturation tanks, and pressure control systems.

In conclusion, DAF system performance depends heavily on influent conditions, chemical control, and hydraulic design.

For more information, please contact: winnie@yihuaep.com