Potential valorisation of ferrous slag in the treatment of water and wastewater: A review

The generation of ferrous slag, an industrial by-product from the iron ore industry, results in serious environmental problems. The chemical compositions indicate 30-34% SiO2, 30-34% CaO, 18-22% Al2O3 and 0.5-0.6% Fe2O3. The specific gravity, moisture content and pH are in the range of 1.3-1.65, 9.1-10% and 8.5-9.0 respectively. The major part of the slag is composed of sand-size particles. The problems of disposal of slag could be minimized by considering its use in various environmental engineering applications providing additional value to the by-product. This paper mainly focuses on the potential utilization and valorisation of ferrous slag in both water and wastewater treatments. It is effective for the treatment of water and wastewater containing nutrients, heavy metals and polluted river/stormwater.