Gasum, the leading biogas plant operator in Finland, has made not one but two new Baltic Sea commitments. The first one is related to development of the use of liquid biogas (LBG) in maritime transport The other aims at reducing nutrient emissions through safe nutrients recycling.
Gasum has committed to developing a concept for efficient nutrient recovery and refining of safe nutrient products from sewage sludge. The concept contains nutrient (nitrogen and phosphorus) recovery from the liquid fraction (reject water) and the solid fraction of the digestate. The process will provide new recycled nutrient products free from hazardous organic compounds for industrial and agricultural purposes.
As the nitrogen is recovered from the reject water, which would normally be lead to a waste water treatment plant (WWTP), it decreases WWTP’s overall nitrogen load and thus significantly improves the plant’s nitrogen removal capacity.
The concept to be developed, will provide a solution for sustainable sewage sludge treatment by combining biogas production and advanced nutrient recovery technologies. The sewage sludge first produces energy and then can be used for safe nutrient products, also for the agricultural use. Thus the nutrient cycle has been closed. The environmental benefits are multiple: production of sustainable energy, reduction of nutrient leakage to the Baltic Sea and decreased need for imported mineral fertilizers.