(562ac) Magnetically Recoverable Carbon-Coated Iron Carbide for Organic and Arsenic Adsorptive Removal

Magnetic particles, generally nanostructured and magnetite-based, have been used extensively to remove drinking water contaminants. Compositions alternative to Fe₃O₄ could address long-standing issues of magnetic recoverability and materials integrity in real waters. The stability, magnetic separability, and adsorptive properties of nanostructured carbon-coated iron carbide (Fe₃C@C) were compared to those of Fe₃O₄ and other common iron oxide-based nanomaterials. Experimental results show that (i) Fe₃C@C is chemically stable in simulated drinking water, (ii) can be separated from water magnetically under flow with greater than 99% recovery, and (iii) has a 100´ higher adsorption capacity for methylene blue (39.8 mg/g) than Fe₃O₄ and a comparable adsorption capacity for arsenic (168 µg/g). These properties suggest Fe₃C@C as a viable magnetic engineered nanomaterial (ENM) for the removal of organics and oxo-anions with further development.