Pumice Media Performance

[Watro]

Gentlemen,

We have plans to use Pumice Media as filtration media instead of Sand for cooling tower applications
These media manufacturer claim to deliver <1 micron of particle size, feed particle size vary from 50 - 150 micron, with TSS of 5 - 10 ppm
Feed Flow rate is 750 m3/hr

Do you have any experience with this media? and the expected results pf PS, TSS, Turbidity and SDI

regards
SH

 

[ashtree]

Being lower specific gravity than sand will give some advantages in backwash, in terms of bed expansion per volume of water used.
As for most of the other claims and suppossed advantages i would suggest that they are marginal at best and may offer only slight improvements if any over conventional sand.
Anthracite may well give the same advantages as the pumice.
Pumice might givce some advantages inthe removal of organics if some biofilm is allowed to grow givedn the "porosity" of the granules.

If your particles are 100% in the 50-150 micron range there is probably better technology than media filters out there to do the job for you given the size and quantity of the particles and throughput required. In water treatment terms those particles are fairly large. But if there is still a significant amount down to say 10micron than media filters may be the correct choice.

If all your particles are 100-150 micron than the TSS turbidity and SVI will all be very low or perhaps zero. However i don't believe that all your particles will be in this size range and that you should go and do more particle size analysis.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[bimr]

Pumice seems to be much more popular in the UK than the US. Perhaps that is because less filter media sand is available is readily available in the UK.

For the cooling tower application, not really sure that higher performance is necessary for a sidestream cooling tower filter system. Suggest that the least expensive option is the way to go.