Hi every body
I want setup a vertical flocculation basin with central input flow to remove metal from plating wastewater tremant, include:
high of basin:1.5m
Diameter of basin: 1.2m
Diameter of central pipe: 0.25m
slope of bottom: 45 degree.
flow velocity: 2m3/h.
I want to know that all parameter above is OK or not? any thing esle that i have to note when design a vertical flocculation basin.
if any one knew about this please help me
thank every body

Nguyen Kien

Hi,
Have you carried out any jar tests, (or bench tests), to check these design parameters?
Are you proposing to include some form of mixing in this flocculation basin, or is the real purpose of this basin intended to facilitate settling?
The flocculation process generally requires mixing to facilitate contact / reaction between the material to be flocculated and the flocculant.
The pace of this reaction can vary depending on the elements involved in the reaction. so I believe that you really should do some jar tests before designing a full scale system.

I am not sure if I understand your explanation properly.
You say that you have a mixing tank before this tank to mix the material to be flocculated and the flocculant, so I expect that flocculation is being achieved in that mixing tank.
Is the second tank then to allow the flocs to develop and grow, or is it to allow the flocculated material to be separated from the liquid?

If it is to allow the flocs to develop and grow then it will need some slow speed mixing (maybe 5 to 7 rpm) and a retention time of perhaps 2 - 3 minutes, (to be defined by bench tests), for this to happen.

If the second tank is to allow the flocculated material to be separated from the liquid, (as is suggested by the sloped cone at the base of the tank, then this is a completely different design altogether.

Can you clarify, please?
Also I have emailed you some further comments and questions.