Triveni provides Dissolved Air Flotation systems for removal of suspended solids and emulsified oil from liquids. For removal of emulsified oil, the emulsion is first broken by the addition of chemicals for which additional flash mixer and flocculation units are provided upstream of Dissolved Air Flotation tank. Flotation of solids is accomplished by introduction of millions of microscopic bubbles into the process water. This is achieved by drawing a portion of the effluent from the downstream end of the DAF tank and pumping the recycled effluent and atmospheric air to a suitable pressure retention tank / saturation vessel. The recycled effluent gets saturated here at elevated pressure in the pressure tank. The air saturated stream is then blended with raw wastewater in the DAF tank. As the pressurized flow is restored to atmospheric pressure in the DAF tank, millions of microscopic bubbles are released which attach themselves to the suspended particles in the flow and lift the particles to the surface for effective removal.

Triveni provides complete DAF systems including the mixing unit, flocculation unit, DAF tank, pressure tank and associated equipment like pumps, compressors, piping, valves, instrumentation etc. The DAF tanks can be provided in both circular and rectangular tank configurations. Either of these tanks can be in steel or concrete construction depending on the flow and size, steel tanks generally being provided for smaller sizes. The rectangular DAF tanks can be provided with either integral or separate mixing and flocculation units.

• Oil skimming device
  An oil skimming device is provided at the downstream end of the separator section for collection and disposal of the oil skimmed to the downstream end by the chain & scraper mechanism. The oil skimming devices generally employed for the purpose are the rotary drum skimmer, the rotatable pipe skimmer and the floating oil skimmer. Refer to the oil skimmer section for the details of these skimmers.
• Mixing & Flocculation Units
  The equipment generally provided for these include the agitators in the mixing unit and flocculators in the flocculation units. The agitators for mixing units are generally vertical motor driven agitator units provided with high efficiency propellers. The flocculators provided for flocculation units are motor driven and can be either horizontal or vertical paddle wheel type depending on tank configuration.
• DAF Tank
  These can be provided in circular and rectangular tank configurations in either steel or RCC construction as per requirement.
  
  The circular DAF tank is provided with equipment which includes bridge superstructure, feed well, drive head, center shaft, rake arms, rotating oil skimmer, oil retention baffle and scum trough for oil collection and disposal.
  
  The rectangular DAF tank can be provided with either integral or separate mixing and flocculation units, each having different inlet arrangements. The internals of DAF tank generally include a chain & flight skimmer on the top for skimming floated scum, a scum screw conveyor, bottom sludge screw conveyor or chain & flight scraper mechanism for scraping of settled sludge, inlet reaction jet baffles / distribution baffle and recycle header at the inlet end and an oil retention baffle at the effluent end of the DAF tank.
  
  The pressure tank is provided with internal baffling for efficient mixing of air with recycle flow.