Fabrication of porous biochar decorated with MnFe2O4 magnetic nanoparticle for high effective removal of Cr(VI) ion in solution.

Heavy metals posed a very important treat to public health and environment because of their toxicity, bioaccumulation and biodegradability properties. The development of high efficiency, low cost and good chemical stability adsorbents for removing heavy metals from aqueous solution was very urgent. The removal capacity of Cr(VI) by the preparation of porous biochar decorated with MnFe₂O₄ magnetic nanoparticle (MnFe₂O₄@PS) was evaluated. Results showed that the operational parameters had an important influence on Cr(VI) removal. Pseudo-second-order model and Langmuir model could be used to describe the adsorption process. The adsorption process of Cr(VI) by MnFe₂O₄@PS composites was a spontaneous, endothermic and randomness process. The removal capacity of Cr(VI) by MnFe₂O₄@PS composites reached 46.51 mg/g. The main mechanisms contained electrostatic interaction, Surface adsorption, surface complexation and chemical precipitation. MnFe₂O₄@PS composites exhibited high removal capacity of Cr(VI), good chemical stability and recyclability. [ABSTRACT FROM AUTHOR]