Bio-sludge treatment

The treatment system

In the Bio-sludge Treatment System all sludge from wastewater and foodwaste is processed. The system is tailor made to secure the interface between liquid and solid sludge before final incineration. The main target for the bio-sludge treatment system is to reduce volume by dewatering, drying and to disinfect. Sludge from wastewater and foodwaste represents a large volume that needs further treatment to align with the environmental requirements for no pollution at sea, the need for a sludge treatment process onboard is obvious. Dewatering of sludge increases dryness to above 20% DM reducing the volume 90%. The reject water from the dewatering is treated in the Scanship wastewater system. To increase the dryness further, all dewatered sludge is treated in a drying process. The process increases the dryness to between 70-80%, reducing its volume down to 5% of its original liquid volume. The end product can be incinerated aboard, used for energy production or landed for reuse. The STTP (Scanship Thermal Treatment System) is our thermal hydrolysis plant for dewatered biowaste and food waste. It enhances downstream dewatering and sterilizes biomass. The STTP process destroys the extracellular polymers of the biomass and releases the internally bound water. The STTP consists of four pressure vessels, treating the bio-sludge and food waste in a multi-stage process before the final centrifuge dewatering. The subsequent centrifuging can achieve close to 50% dry matter, shortening the wet load on the downstream dryers and promoting energy efficiency. The overall gain is reduced dryer size and lower total steam use. We have sold the STTP to ships since 2019.