Mine Wastewater Dissolved Air Flotation Clarifiers and Thickeners

Dissolved air flotation description

---

Dissolved air flotation is a water treatment process that clarifies wastewater by removal of suspended solids, oils, greases, BOD, COD, and metals.

This is achieved by dissolving air in the wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank.

The released air forms tiny bubbles which adhere to the suspended matter causing it to float to the surface of the water where it can then be removed by a skimming device, ready to dewater for proper disposal.

To improve solids removal coagulant/flocculants are added to coax suspended solids and colloidal particles into clumping together.

Dissolved air flotation principle

---

Dissolved Air Flotation is a fairly simple technology using pressurised air to remove small solids, oils, and greases from wastewater.

The physical process happens as follows:

Pressurised air is mixed with pressurised water. Due to the higher pressure, more air is able to dissolve into the water. Pumps with a high energy output are able to achieve complete air saturation of the water.

The pressure control valve causes the high pressure to drop to low. The resulting drop in pressure means that the water is now suddenly over-saturated (supersaturated) with air.

The excess air molecules start to cluster together at existing nucleation sites such as small particles or longer-chain molecules, or surface-active molecule. Since the water is supersaturated instantaneously, the clusters of air molecules stay small, forming very small bubbles.

Buoyancy now causes the bubbles to rise, taking the contaminants with them. Generally, the surface tension of the water keeps particles incased in bubbles once they reach the top of the tank, causing a foam to form which can be easily removed.

Dissolved air flotation technical sheet

---

Dissolved air flotation process flow

---

Dissolved air flotation advantage

---

The effectiveness of DAF units lies in their ability to handle a variety of wastewater streams, making them indispensable across multiple industries.

Whether in industrial settings dealing with complex contaminants or municipal systems facing large volumes of urban runoff, DAF units prove their versatility and efficiency.

They are particularly renowned in industries such as food and beverage production, where they handle organic matter and fats with ease, and in the oil and gas sector, where the separation of hydrocarbons is critical.

Furthermore, the technology is adaptable, with configurations allowing for the introduction of various chemicals to optimize performance based on specific treatment needs.

Beyond their application flexibility, DAF units offer significant advantages including high removal efficiency, low operating costs, flexibility in operation, and a compact footprint.

This makes them a viable solution even for facilities with space constraints or those looking to upgrade their existing wastewater treatment infrastructure.

However, it’s important to note that the complexity of these systems often necessitates skilled operators to manage and maintain optimal performance.

Proper pre-treatment steps such as Coarse Screening, homogenization, sand removal, and coagulation-flocculation are also essential to ensure maximum efficiency and longevity of the DAF units.

Dissolved air flotation feature

---

The environmental impact of DAF systems is generally positive, particularly in minimizing water pollution.

By enabling the removal of over 90% of harmful components from industrial effluents, DAF systems contribute to cleaner water bodies and reduced environmental pollution.

Moreover, reduced chemical usage and advancements in energy-efficient designs further enhance the sustainability of DAF technology.

Dissolved Air Flotation systems have solidified their place as an indispensable tool in modern water treatment processes.

Their ability to efficiently remove suspended solids from diverse wastewater streams makes them particularly valuable across industries with stringent water quality requirements.

As technological innovations continue to evolve, DAF systems are poised to become even more cost-effective and environmentally sustainable, bolstering their role in the global effort to safeguard water resources.

Dissolved air flotation application

---

Wastewater TreatmentDAF systems find applicability across multiple industrial sectors, addressing specific water treatment needs.

Dissolved-air flotation processes have diverse applications across multiple industrial settings.

Common industries benefiting from DAF technology include:

Food and Beverage: The food processing industry utilizes DAF systems to treat wastewater containing high concentrations of fats, oils, and food particles.

Pulp and Paper: DAF is employed to handle process water and to remove suspended solids, enhancing the quality of effluents.

Petroleum and Petrochemical: In these sectors, DAF systems act to remove oils and greases from produced water, significantly reducing environmental impact.

Wastewater Treatment Plants: Municipal treatment facilities use DAF to optimize sludge management and enhance overall treatment efficiency.