Iron nanoparticles supported on N-doped carbon foam with honeycomb microstructure: An efficient potassium peroxymonosulfate activator for the degradation of fluoranthene in water and soil.

Abstract A promising technology was developed for the remediation of fluoranthene (FLT) contaminated water and soil. Specifically, iron nanoparticles supported on N-doped carbon foam (Fe@CF-N) was synthesized by in-situ impregnation and a unique calcination process using pine cone as the precursor. The obtained Fe@CF-N was used as an activator of potassium peroxymonosulfate (PMS) to degrade FLT in water and soil. According to experimental results, Fe@CF-N had a three-dimensional network structure with a large specific surface area of 249.0 m2 g−1, displaying excellent catalytic performance. The maximum removal efficiency of FLT in water and soil reached 81.83% and 78.12% within 180 min, respectively. After four consecutive degradation cycles, the removal efficiency of FLT in water was still 55%. Electron spin resonance (ESR) measurements showed that hydroxyl radicals (·OH), sulfate radical (SO4−·) and 1O2 were the major reactive oxygen species (ROS). A series of low molecular weight intermediates were generated during the FLT degradation progress, such as C6H6O3 and C3H8O2. The effect of Fe@CF-N/PMS system on the phytotoxicity was evaluated via bioassay based on peas. The results indicated that seed germination rate and root shoot elongation of remediated soil by Fe@CF-N/PMS system were not significantly different from those of noncontaminated soil. This study provided a cost-effective remediation option for PAHs contaminated water and soil.