Hydrothermal conversion of waste cartons into a magnetic carbon-iron composite for use as an efficient and recyclable dye adsorbent

Disposal of large quantities of waste cartons aggravates the burden of municipal solid waste treatment. Exploitation of the potential value of waste cartons and conversion of this waste stream into available materials is a hot research topic with practical application prospects. In this study, we successfully fabricated a magnetic carbon-iron composite from waste cartons via hydrothermal treatment and investigated its application as an efficient adsorbent for the removal of a disperse blue dye (DB 56) and reactive yellow dye (RY 3) from aqueous solution. The fabricated product was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer-EmmettTeller analysis. The effects of the composite dose, initial dye concentration, and solution pH on the dye removal efficiency were investigated. Under acidic conditions at pH 2, the removal efficiencies of DB 56 and RY 3 reached 81.53% and 96.77%, respectively. The adsorption processes followed pseudo second-order kinetics and the Freundlich isotherm. The magnetic carbon-iron composite could be easily separated from the aqueous solution because of its magnetism, and could be regenerated by the Fenton reaction. After re-use in three cycles, the removal efficiencies for both dyes were still above 70%. The magnetic carbon-iron composite produced from waste cartons shows promise for application to effluent that contains dyes because of its low cost, high efficiency, and simple application. (c) 2020 Elsevier Inc. All rights reserved.