Case Study 3:
Pulp and Paper Mill with Screw Press / Rotary Screen Thickener

Pulp and Paper Mill

Bleached Kraft (1000 adt/d) and TMP mill, (1400 adt/d) UNOX activated sludge treatment, with primary and secondary clarification.

Design flow: 50 MGD (230 MLD)
Sludge Production: 89 t/day


Equipment: FKC screw press with rotary screen thickener
Old Mixer: Static mixer with throttling valve
New mixer: 6” OPTIFLOC™
Flow: 130 IGPM (10 L/s)
Sludge type: Combined primary and secondary
Composition: 73% primary
27% secondary
Waste paper: 0-10%
Conditioner: Diachem amine based coagulant
Diachem cationic emulsion flocculant


Screw Press with Rotary Screen Thickener (RST)


RST and Screw Press Performance

Static Mixer Optifloc™ Improvement
Feed TS (%) 2.5 2.8
ST Discharge(%TS) 3.4 4.9 44%
Cake TS (%) 30.5 39.2 29%
Pressate TSS(mg/L) 1290 820 36%
Floc.Dosage(kg/t) 9.1 5.0 45%

If you would like to know how the Optifloc™ technology can improve your process Contact Us today!