Regeneration possibilities and application of magnetically modified biochar for heavy metals elimination in real conditions

Although new types of composites with magnetic properties and high adsorption capacity for potentially toxic elements elimination are studied by researcherers, the information about the reusability, stability and removal efficiency of composites is still scarce or absent. Therefore, the aim of our work was applicate the sorbent to eliminate Zn(II), Cd(II) and Pb(II) ions from industrial waste leachates, and moreover, study the composite reusability and magnetic separation efficiency. Magnetically modified biochar was prepared from the fermentation residue of maise hybrid by a simple two-step method with microwave assistance. Composite properties, as well as the adsorption efficiency and magnetic response are depend on the extraction agent. The alkaline extraction agent showed the best properties for reusability and had no influence on Fe releasing from the composite, the adsorption efficiency was higher than 90% even in the 5th recycling cycle, and the composite remained magnetically active. The separation efficiency of composite from an aqueous environment by a magnet was higher than 95% within 15 min. Magnetically modified biochar proved to be an effective sorbent for metal ions elimination from wastewater.