Remediation performance of As-contaminated water and soil using a novel Fe-Mn bimetallic (oxyhydr)oxide coated on natural magnetite.

It is challenging to separate the materials for treating arsenic contamination of soil and water from systems. The natural magnetite covered with Fe-Mn bimetallic (oxyhydr)oxide (Fe-Mn MSM) was effectively created in this study, and its potential use in removing As from water and soil was investigated. Batch adsorption studies showed that the As(V) adsorption on Fe-Mn MSM could achieve equilibrium after 120 min when the initial As(V) concentration was 39.85 mg/L. The calculated maximum adsorption of Fe-Mn MSM for As(V) was 17.94 mg/g at 20 °C. The mechanism of As(V) adsorption was confirmed to be a combination of ligand exchange and electrostatic attraction by the outcomes of FTIR analysis, SEM, and batch adsorption tests. Fe-Mn MSM can also be a successful amendment for cleaning up As-polluted soil. The 5% Fe-Mn MSM treatment group had the lowest exchangeable fraction of As (EX-As) concentration, 0.039 mg/kg (8.3% of initial EX-As), after 40 days. Magnetic separation could be used to quickly and completely recover the used Fe-Mn MSM from the soil. EX-As was present in higher concentrations on Fe-Mn MSM than that of the original soil. As a result, this work offers a strategy that may be put into practice to cheaply remove As from soil and water while also encouraging the reuse of natural magnetite.