Efficient degradation of organic contaminants by magnetic cobalt ferrite combined with peracetic acid

In this study, a novel heterogeneous peracetic acid (PAA)-based advanced oxidation process (AOP), viz. cobalt ferrite combined with PAA (CoFe 2 O 4 /PAA), was used to degrade organic contaminants . The best pH for rhodamine B (RhB) degradation in CoFe 2 O 4 /PAA system was at 7, and approximately 95% RhB could be removed within 10 min at this pH. Radical scavenging experiments indicated that organic radicals (i.e., CH 3 COO • and CH 3 COOO • ) were the dominant reactive species for RhB degradation. The X-ray photoelectron spectroscopy (XPS) analysis for the fresh and used catalysts suggested that the catalytic reaction mainly occurred on the surface of the catalyst. Increasing PAA dosage and CoFe 2 O 4 dosage could enhance the removal of RhB, while excess CoFe 2 O 4 dosage inhibited its degradation probably due to the clumping effect of magnetic nanoparticles . Five degradation products of RhB by CoFe 2 O 4 /PAA were identified and two degradation pathways of RhB were subsequently proposed, including bond cleavage and hydroxylation . CoFe 2 O 4 exhibited an excellent stability and reusability , and the removal rate of RhB could maintain at 92.4% after four cycles. Several kinds of organic contaminants were selected to evaluate the applicability of CoFe 2 O 4 /PAA system, and the results suggested that CoFe 2 O 4 /PAA system exhibited a selectivity for different contaminants.