Preparation and application of nickel copper ferrate and its metal–organic framework composite in the decontamination of chemical indicator contaminated synthetic and raw laboratory wastewater

Abstract

Inefficient decontamination of laboratory wastewater polluted by chemical indicators such as methyl orange (MO) and phenolphthalein (PH) is a challenge that requires attention in most developing countries. In response to this, nickel-copper ferrate (NiCuFeO4) and nickel-copper ferrate-terephthalic acid-zinc metal–organic framework composite (NiCuFeO4@MOF-5) were synthesised via simple chemical process and their activities compared for the removal of MO and PH from synthetic and raw laboratory wastewater colleccted from a science laboratory at Federal Polytechnic, Ede, Nigeria. The scanning electron micrograph (SEM) images, revealed the surfaces of NiCuFeO4 and NiCuFeO4@MOF-5 to be rough and homogeneous with tightly arranged particles that are agglomerated. The adsorption capacity of NiCuFeO4@MOF-5 expressed for the removal of MO (30.97 mg g−1) and PH (41.22 mg g−1) from aqueous solution is higher than that of NiCuFeO4 for MO (25.82 mg g−1) and PH (23.00 mg g−1). NiCuFeO4 and NiCuFeO4@MOF-5 exhibited a promising stability even at the 7th regeneration cycle for the removal of MO and PH from solution. Results obtained for the removal of MO and PH from aqueous solution by NiCuFeO4 and NiCuFeO4@MOF-5 compared favorably with reported adsorbents in literature. Conclusively, NiCuFeO4@MOF-5 is a potential and better adsorbent than NiCuFeO4 for decontaminating laboratory wastewater contaminated with MO and PH.