Activated limestone to reduce the eutrophication in the Baltic Sea

The objective of the project is to demonstrate the usefulness of activated limestone, to reduce the eutrophication in the Baltic Sea.While the nutrient load from land-based sources has decreased in recent decades, phosphorus (P) stored in the seabed is being released from the sediment under anoxic conditions.

A promising product for reducing the phosphorus content is a calcium-based sorbent, activated limestone, developed at Stockholm University. It is produced from a by-product from lime miners (marl) and has ~500 times higher P-uptake that the original marl.

The activated limestone consists of particles with sizes between 2 – 25, they are spread at the water surface and sink to the bottom before they start to react.

The sorbent is innovative, nontoxic, sustainable and cost-efficient.The project aims to apply our previous results under realistic conditions and bring the method to market.

In order to optimize the material will the binding between P and the sorbent be studied.The project consists of four parts:Determination of the bond/interaction between phosphate and calcium carbonate in laboratory studies.Optimization of process parameters and produce 50 tons sorbent.Increase the dosage during the spreading and follow up of the effect of the activated limestone.Development of a business model.With a living Baltic Sea, fish numbers will increase, and toxic summer blooms will diminish, benefitting both the fishing and tourist industry.