Effective and sustainable sludge dewatering

Sludge dewatering is a core element of sludge treatment

The disposal of sewage sludge, sewer flushing and sludges from industrial production, cleaning systems and food production is becoming increasingly expensive, as the legal requirements rise. Sludge dewatering minimizes disposal costs and is therefore a prerequisite for economical operation of many wastewater treatment plants. The investment is normally amortized just by saving on transportation costs after a short period of time.

Sludge dewatering of wastewater treatment plants

There are various technologies for dewatering sewage sludge and other sludges from biological wastewater treatment plants.

All have advantages and disadvantages:

	Screw presses	Chamber filter presses	Sieve belt presses	Decanter-centrifuges
Liquid sludge dewatering	yes	no pre-thickening needed	no pre-thickening needed	no pre-thickening needed
24-h-Operation	yes	no	no	yes
Space required	1	3	3	1
Energy consumption	1	2	2	4
Work intensity	1	2	2	2
Noise	1	3	2	4
Maintenance costs	1	3	3	4
Operational costs	1	3	3	4

 

Conclusion of the comparison: The modern models of screw presses are also suitable for large sewage treatment plants. They reach throughputs of up to 100 m³ / h per machine. Experience has shown that the slightly higher initial inversion (compared to some of the alternative technologies) is amortized within 3 years due to the extremely low maintenance and energy consumption.

 

At sewage treatment plants and biological wastewater treatment plants in industry, the filtrate water can be re-introduced into biological wastewater treatment. High separation rates are – in addition to the dewatering result (measured in percentage of TS content of the mud cake) – another key quality feature of dewatering units.

Dewatering of the fresh sludge counteracts the concentration of the ammonium nitrogen (NH₄-N) contained in the sludges, which otherwise becomes often a burden on “biology”. For continuous sludge pressing, screw presses are ideal. The smaller screw press models from KUGLER, for example, a ready-to-use container solution (no building permission) makes this a worthwhile investment for wastewater treatment plants that have previously been working with dewatering service companies.

Sludge dewatering of inorganic sludge

Almost all types of sludge and wastewater with a high inorganic content can be disposed with the standard KUGLER® dewatering containers. The prefabricated lamella separators from KUGLER are space-saving, easy to install and require only minimal installation work. Because of this combination, they are ideal for places where installation is difficult or expensive. The patented EWC-Lamella from KUGLER combines both – lamella separators and dewatering containers.

 

Find out more about different types of sludge – and the right dewatering aggregates here.

Sludge Dewatering as part of an industrial process