Globally, all modern societies generate a never-ending flow of materials – aqueous waste streams. If waste is composted or incinerated, linear processes are created, the connecting link is missing. However, if the view of treatment changes, cycles become recognizable and thus feasible.
Water is and remains a valuable resource. Too valuable to see its use only in the dilution or transportation of pollutants. Liquid waste streams in particular contain a high proportion of water. The water content contains pollutants that need to be bound. Nutrients are recycled.
Nutrients must be circulated.
We regard wastewater – not as wastewater, but as process water and a flow of recyclable materials. In the end, the scarce resource – water – is cleaned and returned to the water cycle. The recycled nutrients become products in the process and are marketed as valuable materials in the economic cycle.
Nutrients that are in short supply as products such as phosphate fertilizers, biochar or fuel additives on national and global markets and generate high profits.
An important component of the aqueous waste streams is municipal sewage sludge which, in addition to its high water content (>75%), contains important nutrients such as nitrogen (N), ammonium-N, phosphate (P2O5) and carbon (C) as well as pollutants such as heavy metals.
Composition of sewage sludge 25%TS
Another problem that should not be overestimated is the transportability of sewage sludge produced in wastewater treatment plants after treatment in a wastewater treatment plant. In order to make it transportable, it is usually mechanically dewatered at the sewage treatment plant. The term 25% dry matter describes the fact that the sewage sludge contains 25% dry matter (DM) after dewatering, of which only the smaller proportion – the carbon – is combustible, while the water content remains disproportionately high at 75%. The aqueous sewage sludge is transported by truck to agricultural land for seasonal application, incinerated or dumped on large landfills as a legacy for the next generation. New regulations in this area will make it difficult for such an application. A rethink is required and we offer appropriate solutions for this.
The incineration of sewage sludge rules out any economically viable use of the water and nutrients. The cost-benefit principle has no lasting effect. This is because in order to be able to incinerate the moist waste sewage sludge at 850°C, the high water content in the sewage sludge must first be vaporized at approx. 350°C using a great deal of energy.
We offer municipalities the following procedures:
RSR – Procedure
Since wastewater has a certain potential, there must be alternative uses to make daily wastewater usable again, to recycle or reuse it.
The RSR process is characterized as a zero-discharge solution and it can rightly be said that it is an exemplary project with a model effect at regional and supra-regional level. Systems equipped with RSR technology make a significant contribution to achieving the climate targets that have been set.
The addition of an RSR system to a production facility’s wastewater treatment plant helps to significantly reduce the ecological footprint by reducing CO2 emissions. Vital raw materials such as phosphorus, nitrogen, potassium and vital water are recovered. Emissions from the RSR process are harmless, odorless and are released into the atmosphere via filters.
Municipalities and industries benefit directly from the use of the RSR process by saving high transport and disposal costs and optimizing the use of recyclable materials and water resources.
The recovery of phosphorus is also an important future goal for the continued existence of mankind and is enshrined in law. Phosphorus is vital for us and, when used as a fertilizer, helps to improve crop yields. Phosphorus is a limited resource and can only be mined as phosphate. Unfortunately, phosphate deposits are located outside the EU, in countries such as China and Russia. These countries have already imposed export quotas on the export of phosphorus or no longer want to export it at all in future. For this reason, it is important in the EU to recover phosphorus from secondary raw materials such as sewage sludge and waste.
Sludge Drying Systems process (SDS)
From another perspective, it is known that it is very difficult to reduce the volume resulting from sewage sludge processing at wastewater treatment plants and industrial plants under consideration. Known processes already deal with the drying of existing sludge in order to reduce the volume.
Our aim is to use our drying process to carry out drying in an energy-efficient manner and to feed other by-products into the circular economy. By consuming on average less than 90 % electricity and 50 % less thermal energy than our competitors, we are ahead of the competition. This is due to the fact that we can dry up to 90% of the volume of sludge used at a temperature of just 60 degrees.