Home > Case Studies > Recovering algae beds by means of Ferrous Supply Unit / [case study] by Nippon Steel Corp and Keidan

Recovering algae beds by means of Ferrous Supply Unit / [case study] by Nippon Steel Corp and Keidanren Committee on Nature Conservation

This project harnesses the byproducts of two production processes, using steel slag generated in steel production and waste woodchips from forestry, to restore coastal ecosystems affected by denuding, known as “isoyake ”,
It has become clear that a cause of this denuding phenomenon is a lack of iron. While traditionally algae was supplied with bivalent iron (Fe2+) in the form of humic acid from upstream forests, today forestry and development of upstream lands have resulted in a decrease in such iron reaching coasts.
The project utilizes converter furnace steel slag containing a wealth of iron. It is combined with woodchips before being fermented into a man-made mixture that approximates the natural mixture of humic acid. This man-made mixture providing Fe2+ has been used in test cases in Japan, succeeding in restoring seaweed beds at 20 sites, helping to spur a return in fish diversity.
Beyond the scope of practical application, this project has been a success on the research side, such as by revealing the mechanism behind the creation of seaweed beds based on the supply of iron.