Alum sludge production equation

[wpr]

Does anyone have an equation and/or rule-of-thumb used to estimate alum sludge production in a potable water plant? Basically we're continuously removing alum sludge from settling basins and dicharging to a pair of gravity thickeners. We pump from the bottom of the thickeners to a 1 meter belt filter press. I'm guessing 1% solids from the basins, 2% from the thickeners, and maybe 15% from the belt press. Also, what does everyone use for thickener loading rates? I've seen rates from 100 to 200 gpd/sf. thanks

 

[Bigginhk]

Have u ever heard of the UK WRc report TR189, this gives predictions for solids production and guidance on design and operation of sludge thickeners.

If u cant find a copy let me know

 

[bimr]

Alum sludge volume can be calculated using the total chemicals used plus a factor for turbidity.

We just built an industrial water treatment plant (using alum) that has a design solids loading rate of 5 lbs/ft2/day for the sludge thickener.