Kumac reduces the liquid manure and digestate volume by 50% and in a four-stage procedure, clear water, liquid fertiliser concentrate and valuable solid matter are extracted from the source material.
The Kumac processing system works by first separating the solid and liquid matter and then flocculants are added to the liquid manure and digestate. In this way, certain nutrients are fixed, and it becomes easier to separate the solid matter from the liquid phase with the belt filter press.
The drained solid matter has a dry matter content of about 30% and can be used as fertiliser, compost or litter or, in the case of slurry, as biogas feedstock. Subsequently, the remaining liquid phase is passed through a flotation tank in order to separate further small particles and suspended matter. Any remaining solid particles are removed by a fine filter.
In the next step, the filtrate traverses a three-stage reverse osmosis process in order to concentrate salts and nutrients. The resulting liquid fertiliser is rich in nitrogen and accounts for one quarter of the original volume. The major portion of the treatment products consists of clear water (50%), which can be introduced to the water cycle after being processed in the ion exchanger.