Converting waste into a resource: ethylenediamine modification of iron blast furnace slag to fabricate a cost-effective adsorbent for effective Pb(ii) removal

Abstract

The current study represents a new and cost-effective approach to fabricate a potential scavenger for adsorptive removal of Pb(II) from wastewater. Blast furnace slag, a byproduct of the iron manufacturing process, was employed as a key starting material for fabricating an ethylenediamine-functionalized adsorbent (NN@Slag). The spectral, microscopic and N₂-absorption analyses revealed the porous network of NN@Slag and the distribution of amine groups on the NN@Slag surface. The newly developed adsorbent demonstrates a strong potential for removing Pb(II) ions from wastewater, achieving a peak adsorption capacity of 108.04 mg g⁻¹ under optimal conditions: a pH of 6, a contact time of 90 min, a dosage of 0.04 g NN@Slag, and an initial Pb(II) concentration of 100 mg L⁻¹. The EDX spectra and mapping confirmed the effective adsorption of Pb(II) onto NN@Salg. The fitting of Pb(II) adsorption data onto the NN@Slag adsorbent exhibited a strong alignment with the Langmuir model (R² = 0.98998) and pseudo-second order (PSO) kinetic model (R² = 0.98544), indicating that the adsorption process is predominantly governed by a monolayer adsorption mechanism and is significantly influenced by chemisorption.