AEROTHERM™

Thermal sludge conditioning: up to 50% more biogas, and struvite P/N recovery.

The foundation technology of UTB for sludge management, turning waste into value.

AEROTHERM leverages high-efficiency thermal processes to recover valuable resources from wastewater biosolids. By applying controlled heat, it enhances the breakdown of organic matter through hydrolysis and ensures thorough hygienization by eliminating pathogens. The process improves nutrient recovery, reduces sludge volume, and converts waste into usable energy and reusable water, an advanced, sustainable solution for modern wastewater management.

AEROTHERM thermal hydrolysis reactors with insulated pipework and access stairs

How it works

The process

Sludge at 5–6% dry solids is preheated in a heat exchanger and fed to a mixed reactor fitted with an ejector device. Exothermic breakdown inside the reactor carries the sludge to 60–65 °C, hot enough to destroy pathogens and sanitise it, and a biofilter handles the off-gas. The hot sludge passes back through the heat exchanger to recover its heat, then on to anaerobic digestion, where the now more readily biodegradable organics complete their breakdown and yield biogas.

Specifications

Reactor temperature	60–65 °C
Sludge feed	5–6% DS (max 8%)
Energy requirement	3.5–12 kWh/m³ raw sludge
Product	Class A, hygienised and stabilised
Main parts	Mixed reactor with ejector, heat exchanger, biofilter
Operation	Fully automated

Key advantages

Reduced disposal costs
15–25% energy recovery
Carbon for denitrification / P-removal
Liquid fertilizer as a product
Reduction in volume and mass
Smaller post-anaerobic digesters with greater efficiency
Class A sludge suitable for agricultural use
Free from foul odour
Minimal heat input required
Short aerobic reaction time enhances biogas production
Increases the capacity of existing digesters

Insulated AEROTHERM reactors and access stairs at the Kolno sludge treatment plant, Poland

Gallery

AEROTHERM reactor pipework and circulation pump — AEROTHERM reactor pipework

AEROTHERM reactor hall with the tops of the thermal hydrolysis reactors — Reactor hall

AEROTHERM reactor with heat exchanger and insulated pipework — Reactor with heat exchanger

AEROTHERM unit with buffer tanks and dosing equipment — AEROTHERM unit and buffer tanks

Where it is applied

Sludge line

Hygienisation for agricultural reuse
Capacity uprate of existing digesters
Pre-treatment ahead of anaerobic digestion
Odour elimination

123

Plants delivered

Countries

22,323

m³/day capacity

1982

First plant

Case studies

Written up with commissioning data, influent and effluent.

AEROTHERM thermal hydrolysis reactors at the Ekomvo sludge treatment plant, Zielona Góra, Poland

Zielona Gora, EkomvoZielona Gora, PolandIndustrial

Insulated AEROTHERM reactor and pipework at the Ekomvo sludge plant, Zduńska Wola, Poland

Zdunska Wola, EkomvoZdunska Wola , PolandIndustrial

AEROTHERM thermal hydrolysis installation under construction at PUK w Kolnie, Kolno, Poland

Kolno, PUK w KOLNIEKolno, PolandIndustrial

Reference plants

The largest 7 of 123 plants delivered with AEROTHERM, 1982–2011.

Plant	Location	Capacity	Year	Process
Kiskunmajsa	Kiskunmajsa, Hungary	2,000 m³/day	2002	Attisholz
Csurgó	Csurgó, Hungary	1,800 m³/day	2001	Attisholz
Kunágota	Kunágota, Hungary	600 m³/day	2009	Attisholz
WWTP Pribram	Pribram, Czech Republic	105 m³/day	2009	Aerotherm
WWTP Krnov	Krnov, Czech Republic	85 m³/day	2011	Aerotherm
WWTP Wodzislaw	Wodzislaw, Poland	80 m³/day	2004	Aerotherm
WWTP Trebic	Trebic, Czech Republic	65 m³/day	2002	Aerotherm

Search the full reference list →

Have a project?

Request a technical assessment