Biogenic ZVI-banana peel activated carbon nanocomposite: Green fabrication and its application for Cr(VI) and nitrate removal

Abstract

A green synthesized zero valent iron (ZVI) and a physically activated carbon derived from banana peel waste (BPAC) were co-precipitated to fabricate a composite adsorbent (ZVI-BPAC). Fe-SEM and TEM studies reveal the better dispersion of the nano-particles of the composite, lesser particle aggregation and smaller nano-sized dimension as compared to that for the ZVI. Biogenic nature of the composite is indicated by its surface chemical composition (C: 55%; Fe: 24%; O: 19%) as evident from EDAX studies. FTIR studies confirm the successful fabrication of ZVI particles onto the surface of the BPAC. The composite demonstrated good potential for the removal of both Cr(VI) (74%) and NO3– (48.5%) from aqueous medium. The adsorptive removal process was pH dependent with maximum removal occurring at pH 3 at an optimum contact time of 30 mins using a dosage of 0.7 g/L and from an initial adsorbate concentration of 20 mg/L. The study reveals the application of a novel green fabrication process for the development of a biogenic nanocomposite. ZVI-BPAC demonstrated good potential for the significant removal of Cr(VI) and NO3– from aqueous solution.