Coactivation of Hydrogen Peroxide Using Pyrogenic Carbon and Magnetite for Sustainable Oxidation of Organic Pollutants

Abstract

Pyrogenic carbon and magnetite (Fe 3 O 4 ) were mixed together for the activation of hydrogen peroxide (H 2 O 2 ), aiming to enhance the oxidation of refractory pollutants in a sustainable way. The experimental results indicated that the straw-derived carbon obtained by pyrolysis at 500−800 °C was efficient on coactivation of H 2 O 2 , and the most efficient one was that prepared at 700 °C (C700) featured with abundant defects. Specifically, the reaction rate constant (k obs ) for removal of an antibiotic ciprofloxacin in the coactivation system (C700/Fe 3 O 4 /H 2 O 2 ) is 12.5 times that in the magnetite-catalyzed system (Fe 3 O 4 /H 2 O 2 ). The faster pollutant oxidation is attributed to the sustainable production of • OH in the coactivation process, in which the carbon facilitated decomposition of H 2 O 2 and regeneration of Fe(II). Besides the enhanced H 2 O 2 utilization in the coactivation process, the leaching of iron was controlled within the concentration limit in drinking water (0.3 mg•L −1 ) set by the World Health Organization.