Introduction to Dissolved Air Flotation (DAF)
Air supply, pressurising pump, retention tank, and flotation chamber are the four basic components of a flotation system.
The dissolved air flotation (DAF) technique works by bringing suspended particles to the liquid's surface. In most circumstances, DAF is a better option to sedimentation because it provides better ultimate water quality, faster startup, higher rates of operation, and thicker sludge, among other benefits. DAF systems also take up less space than conventional clarifiers, and its modular components make installation and setup a breeze.
Introduction to Aerobic waste water treatment systems
Aerobic wastewater treatment is a biological technique that breaks down organic impurities and other pollutants such as nitrogen and phosphorus using oxygen. A mechanical aeration device, such as an air blower or compressor, continuously mixes oxygen into the wastewater or sewage. The organic stuff in the wastewater is subsequently consumed by aerobic bacteria, which convert it to carbon dioxide and biomass, which may then be eliminated.
The aerobic treatment of wastewater and sewage can be accomplished using a variety of technologies. These are some of them:
v Activated Sludge: Organic matter is broken down by aerobic microorganisms in an aeration tank in traditional activated sludge. Biological flocs (sludge) are formed, and the cleaned water is separated from it in a sedimentation tank.
v Moving bed biofilm reactor (MBBR): Biofilm grows on plastic carriers suspended and circulated in an aeration tank in a moving bed biofilm reactor (MBBR). Retention sieves keep these in the tank.
v Membrane bioreactor (MBR): A cutting-edge technique that combines the activated sludge and membrane filtration processes.
Which are best DAF or Aerobic Wastewater Treatment systems?
1: Dissolved Air Flotation
Many drinking water treatment plant employ dissolved air flotation technology (also known as DAF water treatment equipment).
Since 2000, DAF water treatment has been used in more than 50 drinking water treatment plants across India. These plants can handle anything from 0.5 MGD to 290 MGD of wastewater.
Manufacturers of dissolved air flotation systems include a flotation tank, a recycling pump that draws recycle water from effluent water, and an air drum that saturates the recycle water with air. Feed water is pumped into the flotation tank, and effluent water is pumped out. The effluent water is pumped into an air drum with recycled water.
Compressed air is added into the recycle water as it passes through the air drum. The compressed air is forced to dissolve into the recycled water because the air drum is pressured. The recycled water is re-circulated into the flotation tank, where the pressure is decreased, allowing the dissolved air to escape. The bubbles cling to solid particles in the flotation tank's water and brings them to the surface, where they form a froth layer that a skimmer or lamella clarifier separates from the effluent water.
2: Aerobic Treatment Systems
A pretreatment step, an aeration stage, a settling stage, and a disinfection stage are all part of an aerobic treatment system.
The aeration stage, which involves the introduction of air, is the most similar to a DAF wastewater system. A biomass digests biological wastes from the wastewater during the aeration step. The biomass must be exposed to air since digestion is an aerobic process, and the biomass thrives in an aerobic atmosphere.
The primary difference between aerobic treatment systems and dissolved air flotation systems is the purpose of the air that is added into the wastewater.Air is introduced to induce solids to float to the surface in a dissolved air flotation system, while air is introduced to promote biomass digestion of biological waste in wastewater in an aerobic treatment system.