Green Sentinel

Pollution & Health Circular Economy

From waste to recyclables with the RSR process

Project Facts

Wels, Upper Austria

Project Dates
Start: 2020
In operation since/from: 2023

The Story

Green Sentinel has developed a process for the best possible treatment of sewage sludge in order to transform sludge, which is considered waste, into productable recyclables and essential resources in the sense of the circular economy. The developed zero-discharge "RSR process" ("Recovered Sludge Resources") recycles the valuable materials contained in the sludge, such as the vital phosphorus, and allows the extraction of a high-quality fertiliser as well as, in a further optional process step, the production of a purified CO2-neutral biofuel. A first plant is being planned and is to be implemented by the end of 2022.

Success Factor | Hero Moment

The RSR process and the products generated from the process do not yet exist on the market in this form and represent a real innovation. Green Sentinel rethinks circular economy by closing biological or technical cycles: recovering valuable materials (such as phosphorus, nitrogen, potassium, calcium) from sewage sludge and converting them into reusable products, such as quality compost or a CO2-neutral biofuel. By using the RSR process, the ecological footprint can be significantly reduced, therefore contributing to climate protection. Sewage treatment plant operators currently have to pay high transport and disposal costs for the sewage sludge produced, which is then disposed of via mono incinerators. With the RSR process, these costs as well as CO2 emissions can be reduced.

Green Sentinel GmbH, Austria

Contact Mail


Waste Treatment, Waste Collection, Waste Management