Coagulant for Alkaline Waste Activated Sludge
Coagulant for Alkaline Waste Activated Sludge
(OP)
I am currently working on a project to chemically treat WAS to increase its dewaterabilty. The end result being a very alkaline sludge of around 12 pH units. We currently use Ciba Zetag 87 polymer but I would be interested to hear of any other polymer solutions that would give better performance at such a high pH. Thanks
Paul





RE: Coagulant for Alkaline Waste Activated Sludge
First, what are your goals;
(1) Dewater sludge to reduce transportation and disposal costs?
(2) Reduce chemical costs?
(3) Produce a Class A biosolid?
Second,
A.Contact a water treatment chemical company and request that the sales person visit you; several excellent companies are:
(1) Nalco Oneda
(2) Betz
(3) Chemtreat
(4) Drew Industrial (Division of Ashland Chemical)
B. Have the salesperson conduct a jar study.
C. Have the salesperson submit a proposal with a ROI.
Sincerely,
Todd Foret
toddforet@usa.net
RE: Coagulant for Alkaline Waste Activated Sludge
The primary goal of the project is to reduced transport/disposal costs, secondary to that is the production of a class A biosolid. Additional benifits include the reduction in the polymer demand (saving of ~3kg active ton-1 dry solids)of the sludge so I guess you could say that all three goals are met. Do you have any experience with the new crosslinked polyacrylamide polys? Thanks
Paul
RE: Coagulant for Alkaline Waste Activated Sludge
If you are using a sodium based product, that will decrease your dewaterability and usually increase the amount of polymer needed. Alum also will have a negative effect on dewatering. Are you using lime in the sludge before dewatering to increase the pH for your class A requirements? If so, that kills polymers very quickly.
Mike Bensema
www.dutchmenservices.com
RE: Coagulant for Alkaline Waste Activated Sludge
If your primary goal is to reduce transportation and disposal costs then you need to dry the sludge to "bone dry."
I can send you information on a cost-efficient mobile sludge dryer.
Sincerely,
Todd Foret
toddforet@usa.net