Valorization of nano-scrap carbon iron filings as heterogeneous electro-Fenton catalyst for the removal of anticancer drug: insight into degradation mechanism

This study employs mechanically synthesized nano-scrap carbon iron filings (nSCIF) as a cost-effective and sustainable catalyst in heterogeneous electro-Fenton process. The catalytic behaviour of nSCIF was studied for the oxidation of cytarabine (CBN) under the influence of various experimental parameters such as pH, catalyst dose and applied current density. The highest removal efficiency (~ 99%) was achieved in 90 min of reaction at pH 3, 0.4 g L⁻¹ of nSCIF dose and applied current density of 40 mA cm⁻². Being a solid catalyst, nSCIF enhances the production of •OH radicals and promotes the cathodic regeneration of iron species (Fe³⁺ to Fe²⁺). The mineralization efficiency reached 78% within 3 h of reaction time. The daughter products generated during the reaction were identified through mass spectrometry analysis where eight major transformation productions were identified. The degradation of CBN was mainly contributed by the oxidation of aromatic ring. These findings corroborate the potential of utilizing industrial waste in the electrocatalytic oxidation of persistent pollutant.

Graphical Abstract