Cambi to deliver thermal hydrolysis technology in Bulgaria

Cambi is currently working on its first thermal hydrolysis project in Bulgaria, for Sofiyska Voda’s Kubratovo wastewater treatment plant in Sofia.

Through Cambi’s thermal hydrolysis technology (THP), sludge treatment yields nutrient-rich, pathogen-free biosolids appreciated by farmers in many countries. In Sofia, the process will reduce the total annual biosolids volume by 50,000 tonnes, resulting in tremendous savings in handling costs. THP also boosts biogas output by 30%, generating enough green electricity for 10,000 Bulgarian families.

The project is the result of a joint initiative between Cambi and Green Business Norway, promoting the Cambi THP solution as the best available technology for the Kubratovo project.

We look forward to collaborating with the consortium DZZD “SWWTP – Kubratovo” in delivering Cambi’s first thermal hydrolysis project in Bulgaria”, said Eirik Fadnes, Cambi CEO.

Fadnes Eirik
The project is funded by EU structural funds and is intended to fulfil more stringent environmental criteria and ensure adequate treatment for increasing wastewater inflows until 2050. Thermal hydrolysis allows the facility to adapt and comply to future changes in sludge treatment standards in a cost-effective manner.

It is exciting to see the response in the Bulgarian market, for such a pioneering technology. We believe the Kubratovo project will bring more investments into sludge treatment in this part of Europe, boosting the local circular economy in cities throughout the region”- said Madlena Vladimirova, Green Business Norway Market Director for Bulgaria.  


The contract is part of a broader project in which Sofia Municipality is renovating and extending the Kubratovo wastewater treatment facility, one of the largest in the Balkans. The project will provide major environmental and economic advantages to the municipality of Sofia.

The Kubratovo thermal hydrolysis facility is expected to be operational by the end of 2023.

For further information contact:

Thor Sverre Minnesjord, CEO Green Business Norway

Madlena Vladimirova, Market Director Bulgaria Green Business Norway