Dissolved Air Flotation Unit in Wastewater Treatment

Dissolved air flotation unit is a device used in wastewater treatment.

It helps remove suspended solids from water. This is useful for industrial wastewater and municipal water systems. The unit uses air bubbles to lift particles to the surface. Then, the particles are removed from the water.

The process starts by adding chemicals to the water. These chemicals include coagulants and flocculants. Coagulants help small particles stick together. Flocculants make the clusters bigger. After mixing, the water goes into a pressurized tank. Air is added into the water under high pressure.

Next, the water is released into a flotation tank at normal pressure. This change causes the air to form small bubbles. These bubbles stick to the suspended particles. The bubbles make the particles float. A scraper at the top of the tank removes the floating layer. The clean water flows out from the bottom.

This method is good for removing total suspended solids.

It also helps reduce chemical oxygen demand (COD) and biological oxygen demand (BOD). The system is often used in food processing, oil refineries, and textile industries. It is also used for water recycling.

There are two main types of DAF units. One is rectangular. The other is circular. The rectangular unit needs more time. The circular unit works faster and uses a spiral scraper. Both can treat different kinds of wastewater.

In some systems, DAF is used before biological treatment. It removes grease, oil, and solids early. This helps reduce the load on later stages. In other cases, DAF is used at the end. It polishes the water before discharge.

DAF is also used with other systems.

For example, it can work with MBBR media or sand filters. This makes the whole treatment process more stable and efficient. It helps meet discharge limits for water pollution.

Industries like using DAF because it is simple. It works well and needs less space than other systems. It removes padatan tersuspensi, or suspended solids, without using many moving parts. It is easy to control and can be scaled up.

DAF units are helpful for removing light particles. These include algae and oil drops. These are hard to settle using gravity. But DAF can float them. This is why DAF is better than sedimentation for some uses.

Some DAF units use lamella plates. These plates give more surface area. They help with particle separation. This makes the system faster and more compact.

In systems that treat limbah industri, or industrial wastewater, the DAF unit is key.

It protects biological systems. It also makes sure that pollutants do not enter the environment.

Using DAF systems also reduces sludge. The sludge removed is easier to dewater. This lowers handling costs.

The bubbles in a DAF unit are very small. These microbubbles are important. They can reach and stick to tiny particles. Bigger bubbles would not work as well.

When designing a wastewater treatment facility, engineers often choose DAF units. They are flexible and fit many needs. For example, they help treat air limbah, or dirty water from industrial plants.

Some DAF systems use dissolved gas instead of air. This is called dissolved gas flotation. It is used in oil and gas plants. It lowers the risk of fire. In these cases, nitrogen is used instead of oxygen.

DAF units also help with water reuse. Cleaned water can be sent back into the process. This saves money and water. It also reduces the need for fresh water.

The main parts of a DAF system are the air tank, pressure pump, floatation tank, and skimmer. Each part is simple. Together, they make a powerful tool.

Because of these reasons,

dissolved air flotation is popular. It helps remove oil, grease, and solids. It helps meet regulations and keeps the environment safe.