Iron doped phenolic resin based activated carbon micro and nanoparticles by milling: synthesis, characterization and application in arsenic removal

Abstract

In this study, we have prepared iron-doped activated micro/nano carbon particles as efficient adsorbents for arsenic removal. Starting with phenolic resin monomers, polymeric spherical beads of size ˜0.2-1 mm were first synthesized by suspension polymerization. Iron (Fe) was incorporated in an intermediate step during polymerization. The internal porous structure was developed in the Fe-doped polymeric beads by carbonization followed by physical activation using steam. Subsequent to activation, beads were milled to prepare the micro/nano particles in the size range of 100-500 nm. In an alternate route to preparing the adsorbents, the synthesized polymeric beads were first milled and then carbonized and activated. The absorbent particles thus prepared were applied in the removal of arsenic (III and V) present at low concentration levels (<20 mg/L) in water. The method in which milling was performed first produced a superior adsorbent. For both the ions, the equilibrium loading (˜3-15 mg/g) in the adsorbate were found to be comparable to the adsorbates reported in literature. The simple and up-scalable methodology developed in this study has the potential for the preparation of a wide variety of similar metal impregnated porous (polymeric precursor based) adsorbents/catalysts in other environmental remediation applications.