Recycling of White Steelmaking Slag: A Novel Solution for Acidic Soil Remediation in Southern Italy within a Circular Economy Framework

Acidic soils in southern Italy (Sicily, Calabria, Apulia, Basilicata, and Campania) represent a serious agricultural and environmental challenge. Relatively high rainfall, leaching of basic cations, and long-term use of ammonium-based fertilizers have reduced soil pH to the range of ۵–۵.۵, severely affecting the yield of strategic crops such as durum wheat, olives, citrus, and grapes. The traditional liming method using mined limestone, besides high economic costs, involves considerable CO₂ emissions and quarry degradation. This paper introduces the novel solution of using white slag from Electric Arc Furnace (EAF) steelmaking as a soil amendment. This by-product has a calcium carbonate equivalent (CCE) of ۵۰–۷۰%, contains soluble calcium, magnesium, and silica, and has been officially recognized as a "soil amendment fertilizer" by the Italian Ministry of Environment and Agriculture (recent decree of ۲۰۲۵). The circular economy approach, by transporting slag from steel plants in northern Italy to acidic soils in the south, not only reduces industrial waste landfilling but also provides a suitable alternative to limestone, cutting CO₂ emissions by up to ۴۰%. Preliminary test results show that applying ۱ to ۳ tons per hectare of white slag raises soil pH to the neutral range (۶.۵–۷), increases cation exchange capacity, and supplies plant-available silica for stress-resistant crops. Emphasizing environmental engineering aspects (waste management, life cycle assessment, soil pollution, and sustainable logistics), this paper presents an operational model for implementing this solution in southern Italy.

کلیدواژه ها:

White slag ، acidic soil remediation ، circular economy ، industrial waste management ، southern Italy ، environmental engineering