Metal in waste water?

Question

We mix mineral compound for produce multivitamin tablet. Minerals and other material mix together in mixer(0,5 m³).
When clean the tank with 2% NaOH solution, the concentration of mineral increase in waste water
Cr 840 mg/liter
Cu 2,0 mg/liter
Mo 20 mg/liter
Se 20 mg/liter
Zink 110 mg/liter
COD (Cr): 27000 mg/liter
We want to reduce the mineral to minimum.
which process can we select ?
Which flocculant;coagulant and precipitant can select?

Best regards

Answer 1

Most solids can be removed using simple sedimentation techniques with the solids recovered as slurry or sludge. Very fine solids and solids with densities close to one pose special problems. In such case filtration or ultra-filtration may be required. Alternatively, flocculation may be used using alum salts or the addition of poly-electrolytes.

Answer 2

I found the following link to a company that does this chemistry as a business. It may not be the free answer you were hoping for, but you might learn something by investigating them further.

http://www.watertreatmentsupply.com/wastewater-treatment/Heavy-Metal-Removal.htm

Here is another site sponsored by ASCE which may be of help

http://www.pubs.asce.org/WWWsrchkwx.cgi?Coagulation