Case Study : Digested Sludge Dewatering at Biogas Plant


Sludge treatment is a critical challenge for biogas plants, where food waste is transformed into renewable energy. The resulting digested sludge/digestate – a byproduct of biogas production – must be dewatered efficiently to reduce waste and enable reuse.
In this case study, we explore how Kendensha’s KDS Dewatering System revolutionised wastewater treatment at a biogas plant.
Why Sludge Dewatering Matters
Biogas plants convert organic waste into energy, but the leftover sludge can be tricky to manage. Without proper dewatering, it is costly to dispose of and harmful to the environment. The KDS Dewatering System offers a sustainable solution, turning sludge into reusable fertiliser while minimising operational costs.
When a new biogas plant was built in July 2023, its operators chose the KDS Dewatering System after demonstration tests showed:
Unmatched efficiency: Superior solids recovery compared to competitors.
Lower costs: Reduced running and maintenance expenses.
Eco-friendly output: High-dryness sludge
System Specifications
Facility | Biogas Plant |
---|---|
Wastewater/Sludge | Anaerobically digested sludge from food residue |
KDS Products | KDS Dewatering System + Polymer Preparation System + Polyferric Sulphate Feeder |
KDS Separator Model | Dewatering Pneumatic : SS-811DK 1.0mm |
Power Consumption | Dewatering System : 1.75kW, Chemical Feeding System : 1.3kW (excluding pumps) |
Installation | July, 2023 |
Performance Data
Influent [mg/L] |
Filtrate [mg/L] |
|
---|---|---|
SS | 15,000 | 37 |
BOD | 410 | 29 |
COD | 4,400 | 190 |
N-hex extract | 120 | 3.3 |
SS Rcovery Rate | ||
---|---|---|
99.8% | ||
Discharge Cake Dryness | ||
25% |
Current Performance
Flow Rate [m3/hr] |
Solids Content [%] |
Throughput [kgDS/hr] |
Powder Flocculant Dosage [mg/L of Influent] |
Operation Hours per Day |
---|---|---|---|---|
2.7 | 2.5 | 68 | 750 | 8 hours |
Before & After


Customer Feedback
We anticipated 15% cake dryness, but the KDS system consistently achieves over 25%. This has slashed energy use in our sludge dryer, saving significant costs. We’ve also reduced polymer flocculant usage, making operations even more efficient.
The KDS system is a game-changer.
See the KDS System in Action
On video page, you can find various wastewater/sludge treatment with Kendensha products.
Please check!