Chemical phosphorus removal

Hi Enrico,

A question about chemical phosphorus removal. In case that the chemical phosphorus removal takes place in a primary settling (before de biological reactor), the alum o iron block can be disposed in the model before the primary settler? My doubt appears in the fact that maybe WEST needs the existence of a biological reactor to activate the precipitation and redissolution processes of the ASM2d….  and with a primary settler block those reactions do not take place. If so, what would you recommend? Maybe to install an ASU block with a negligible volume just before the primary settler block?

Thanks indeed!

Hey Hector,
in short: all YES :)
My only remark is that I would place the tank AFTER the primary settler; and not necessarily with a negligible volume - which may result in numerical instability. In that position, there should be negligible oxygen, nitrates and biomass in the stream, thus no significant bioprocess should take place anyway.

Thanks Enrico. Very useful your answer and quick as lightning!

Ops, sorry!
I did suggest to place the tank after the settler. This is clearly nonsense: it should go BEFORE, as you initially suggested.