Danieli & C. in collaboration with Politecnico di Milano, designed an innovative, patent pending, treatment plant to solve some issues associated to metals leaching (i.e., Ba, V, and Cr), and high free lime concentration for carbon steel EAF slag, for the production of artificial aggregates featured by mechanical properties suitable for the building purposes. The plant is featured by an innovative pneumatic transport system to convey the stabilizing agent to intercept the molten slag flux during the deslagging operation. The new system promotes stable microstructural phases' formation, able to retain metallic ions leaching, maintaining the same mechanical properties of the as-cast slag. The main advantages of the new implemented stabilization plant are a simple installation and an easy process operation.

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Operating conditions strongly affect the productivity of photobioreactors (PBRs). Even though it is demonstrated that continuous systems allow higher biomass productivity, the use of the semicontinuous mode is more widespread for technological reasons. However, even on such a system, tuning the residence time can improve production, in particular if the solid retention time (SRT) is adjusted. Conversely, the hydraulic residence time (HRT) should be set to minimize nutrient loss. In this work, a previously implemented model was applied to a 3.4 m 3 , artificially illuminated pilot plant cultivating Arthrospira platensis, to define the best operating conditions in terms of SRT, which is often neglected in the common operating procedures. This new approach that combines modeling and management of operating conditions allowed obtaining a biomass productivity of 0.8 g L −1 day −1 , more than 3 times higher than that obtained in the same system operated with standard procedures (0.24 g L −1 day −1 ), even though the stability of the production is strongly related to the efficiency of the separation system. The SRT also influenced the protein content of the biomass, which was found to increase at lower residence times. Finally, by optimizing the culture medium in terms of the carbonate/bicarbonate ratio, a higher CO 2 exploitation was obtained.