Magnetically separable Fe-base deposited on different carbon sources for ultrasound/persulfate-like heterogeneous activation: Optimized synthesis and field driving process

The eco-friendly composite materials, micro-nano Fe-base/glucose-derived hydro-chars (Fe_b/HCs), were prepared, whose magnetic separation can be achieved in both preparation and water treatment stages. The performances of Fe_b/HCs after N₂ heat-treatment to activate persulfate, chlorite, hydrogen peroxide, etc., in ultrasound field, obtained great improvement by extracting “O”. For comparison, other different sized and magnetic iron-carbon based composites based on different carbon sources of activated carbons, cornstalk-derived bio-chars, and glucose-derived pyrolytic carbons were prepared and applied to systematically compare the performance of activation. The Fe_b/HCs with optimizing preparation were utilized as activators to well treat different structures (triphenylmethane-, azo-, and xanthene-) contaminants. The detected p-Benzoquinone and 2-chloro-p-Benzoquinone could be considered as transitional and characteristic intermediates from carbocyclic compounds to chain compounds. The degradation mechanisms were evoked by pH and absorption to trigger via free/non-free radicals processes: high valence iron-oxo species, sulfate radicals, hydroxyl radicals, Cl-based substances, etc. The findings contrastively provided the potential applications of magnetically separable iron-carbon based composites for heterogeneous activation in environmental remediation.