Dear Vahid! DAF is very ...

Dear Vahid!

DAF is very well suited as pre treatment for desalination in areas where algae blooms and similar events occur (oil spills). It will very effectively reduce the algae content to more than 90% in most cases. Often, additional membrane treatment is required anyway for small organic substances not removable by flotation, but harmful for RO.

As others have written, iron based coagulants are best and aluminium based ones are not desired in desalination. Using polymers is effective, but must be very well considered, as they are very harmful for the RO. Many RO manufacturers require NO cationic polymer at all, because they cause strong fouling. 

Depending on the intake water quality it might not be required to run a DAF system at all times. However, it should be running on stand-by, in order to get it started fast in case of intake water quality change. Depending on the water temperature and salinity, conventional DAF systems can be inefficient with a very high energy consumption due to thermodynamic laws (decreasing solubility of air in water). Especially in those cases, technologies like akvoFloat are superior. 

Best regards, Johanna