Synthesis and adsorption of Fe-Mn-La-impregnated biochar composite as an adsorbent for As(III) removal from aqueous solutions

Groundwater with elevated As concentrations is a global concern, and low-cost, high-efficiency removal technologies are necessary. Therefore, we have prepared three adsorbent Fe-Mn-La-impregnated biochar composites (FMLBC5) for the efficient removal of As(III) from aqueous solutions and characterized them using a variety of techniques. We found that the efficiency of As(III) removal increased with increasing La content and that the removal mainly occurred via adsorption and oxidation. Moreover, the removal of As(III) by FMLBCs was rapid and was best fitted to a pseudo-second-order kinetic model. The adsorption isotherms were well described by the Langmuir equation, and the maximum As(III) adsorption capacity was 15.34 mg g(-1). These results highlight the significant potential of FMLBC5 as adsorbents for As(III) removal from aqueous solutions. (C) 2019 Elsevier Ltd. All rights reserved.