Remediation of Chromium (VI) from Groundwater by Metal-Based Biochar under Anaerobic Conditions

Iron salt-modified biochar has been widely used to remove Cr(VI) pollution due the combination of generated iron oxides and biochar, which can bring positive charge rich redox activity. However, there are few comprehensive studies on methods modifying with different salts. In this study, two salt (FeCl3 Fe(NO3)3) modification were prepare Fe-modified materials for removing in simulated groundwater environment. It was revealed by systematic characterization that FeCl3@BC prepared via FeCl3 method, larger pore size, higher zeta potential oxide content, adsorption-reduction performance efficiency as compared Fe(NO3)3@BC Fe(NO3)3 method. Combined XRD XPS analyses, Fe3O4 is key active component reduction Cr(III). The experimental results have shown acidic conditions promoted removal, while competing ions (SO42? PO43?) inhibited removal FeCl3@BC. Elovich model intra-particle diffusion describe adsorption behavior well, indicating both high activation energy process control Cr(VI). Freundlich (R2 > 0.999) indicated unevenly distributed chemisorptions centers surface. Stability experiments exposed stable under neutral, acidic, alkaline conditions. Furthermore, main mechanisms include electrostatic adsorption, chemical reduction, ion exchange, co-precipitation. conclusion, our findings provide a new insight selection methods, will also be beneficial preparation more efficient biochars future.