Dissolved Air Flotation (DAF) Technology
DAF is the heart of our MWTS. DAF – Dissolved Air Flotation, is technology that has been in use for almost a century. Our innovation of DAF technology is reinforced with 11 patents granted in the past 16 years, 5 patents active, and 3 patent applications on file for the continued advancement of DAF and new Evaporator technology.
Historically, the standard DAF treatment capacity was 50+ microns and current competing technologies can typically treat down to 10-15 microns at best. Our DAF can treat contaminants down to one micron. This means that even the smallest contaminants cannot get past our DAF.
If contaminants are present in solution, which essentially means that contaminants are no longer in the water but are a part of the water, our DAF teams up with the best membrane technology, to make our MWTS able to address every water treatment need.
DAF is a method of coagulation-flocculation used as pretreatment for contaminated source water. Since DAF is particularly well suited for the removal of algae, unwanted coloring, and lighter particles (such as dust and clays) that resist settling out of treated source water, employing this technique before desalinization (RO) reduces clogging from organics that cause maintenance problems downstream from delicate filtration membranes. Where we encounter highly turbid waters caused by denser (heavier) particles. When the DAF is in action, the influent fills the DAF at a rate of 280 gpm for standard DAF, 830 gpm for MAGNA MWTS, and up to 35 gpm for the Micro-Flow MWTS.
When necessary, a chemical coagulant or flocculent may be added, such as iron salts, aluminum salts, or polymers, to the source water to facilitate bonding among particulates. Coagulants work by creating a chemical reaction, eliminating negative charges that cause particles to repel each other. Mixing the coagulant and source water is a process known as flocculation. The churning of water induces particles to collide and clump together into larger and more easily removable 'clots' or “flocs.” The flocculated water is pumped into our DAF tank where the water is subjected to a large infusion of tiny, pressurized air bubbles. The action of these bubbles floats 'clots' of particles to the surface of the DAF tank where they are skimmed off to a waste tank for disposal.
DAF is an excellent alternative to sedimentation. It performs a similar task by an opposite method—forcing coagulated contaminant clumps that are flocculated to the surface rather than allowing them to settle out on the bottom.
- Raw Water enters pre-treatment at approximately 280 gpm
- pH and water temperature measured
- Raw water mixed with coagulant in in-line static mixer, if necessary
- Pumped to Dwell Tank for up to 5 minutes
- If necessary, mixed with flocculent in in-line static mixer
- Pumped into clarifier - heavy wastes fall out and pumped into waste tank
- Clarified water disinfected
- Pumped to DAF Tank where dissolved air introduced
- DAF process water is drawn to DAF Pump Feed Line to make DAF bubbles
- Contaminants floated to top of DAF tank and skimmed off
- Contaminates washed off skimmer and into a collection tank
- Clean water drawn off bottom of DAF Tank (excluding TDS)
- Clean water pumped through media filters (excluding TDS)
- Clean water pumped through carbon filters (excluding TDS)
- Pumped to de-salination process (RO) (if needed) where TDS/Salts are removed to produce drinking water
- Clarifier sludge and backwash from filters collected in Waste Tank - mixed with DAF Sludge
- De-watered by filter press, belt press or centrifuge
- Water from the above process returned to system intake and processed again
- Clean RO Water to Clear Well
- RO Brine to Evaporator