Towards advanced industrial waste-based magnetic activated carbons with tunable chemical, textural and magnetic properties

The control of chemical, morphological, textural and magnetic properties developed in magnetic activated carbons (MACs) from industrial food waste, was achieved. The process parameters involved in a sustainable and optimized one-step activation route, based on the circular economy model, played an important role and its influence was studied, offering interesting and outstanding results. Magnetite crystals were formed on the MACs surface obtained from 400 degrees C to 800 degrees C while other iron species, such as metallic iron and iron carbides, were formed only at 800 degrees C. Acid washing favored the mineral matter removal and the presence of iron species was drastically reduced in acid-washed MACs, mainly the iron species originated at 800 degrees C. Water-washed MACs presented better magnetic response at high temperatures (confirmed by XRD, FTIR, Raman, Mossbauer spectroscopy and VSM characterization techniques). High BET surface area (approximate to 822 m(2)/g) and a large micropore volume (approximate to 0.30 cm(3)/g), were reached by acid washed MACs at 800 degrees C. The obtained MACs were fundamentally microporous, but some mesoporosity was also observed when activating agent/precursor mass ratio (1:1) is used. It can be concluded that a MACs strategic design was reached with the objective of removing specific pollutants in multiple environmental applications.

Automated summary

The study successfully achieved control over the chemical, morphological, textural, and magnetic properties of magnetic activated carbons (MACs) derived from industrial food waste. By using a sustainable and optimized one-step activation route based on the circular economy model, the researchers obtained interesting and outstanding results. Acid washing of the MACs led to better magnetic response at high temperatures, with higher BET surface area and micropore volume.