Lignosulfonate-Assisted Hydrothermal Synthesis of Mesoporous MnFe2O4 and Fe3O4 for Pb(II) Removal.

The development of efficient magnetic adsorbents is highly desirable for water treatment. In this work, MnFe2O4 and Fe3O4 were prepared by a lignosulfonate-assisted hydrothermal method. The structure, surface property and adsorption capacity of the products were investigated. The obtained products have a small amount of carbonaceous materials, mesoporous structure and narrow pore size distribution. In comparison with the samples prepared without lignosulfonate, they have more surface hydroxyl groups and highly negatively charged surface in aqueous solution, which favor the adsorption of cations. Fe3O4 and especially MnFe2O4 exhibited high adsorption capacity towards Pb(II). The maximal removal efficiency of Pb(II) (50mgL) on MnFe2O4 was 100% at pH 6.2. The results demonstrate that this method is promising for the synthesis of magnetic adsorbent. Mesoporous MnFe2O4 and Fe3O4 containing a small amount of carbonaceous materials were successfully prepared by a simple lignosulfonate-assisted hydrothermal method. The as-obtained samples exhibited high adsorption capacity for Pb(II) removal due to their abundant surface hydroxyl groups and highly negatively charged surface. [ABSTRACT FROM AUTHOR]