Magnetic EDTA functionalized CoFe2O4nanoparticles (EDTA-CoFe2O4) as a novel catalyst for peroxymonosulfate activation and degradation of Orange G.
EDTA functionalized CoFe2O4nanoparticles (EDTA-CoFe2O4) synthesized using a facile one-pot solvothermal method were employed as catalysts to activate peroxymonosulfate (PMS) with Orange G (OG) as the target pollutant. Effects of operating parameters including initial solution pH, catalyst dosage, PMS dosage, and water matrix components such as Cl-, NO3-, CO32-, and humic acid were evaluated. A degradation efficiency of 93% was achieved in 15 min with 1 mM PMS and 0.2 g/L EDTA-CoFe2O4catalyst, while only 57% of OG was degraded within 15 min in CoFe2O4/PMS system. The degradation of OG followed pseudo-first-order kinetics, and the apparent first-order date constant (kobs) for OG in EDTA-CoFe2O4/PMS and CoFe2O4/PMS system was determined to be 0.152 and 0.077 min-1, respectively. OG degradation by EDTA-CoFe2O4/PMS was enhanced with the increase of catalyst and PMS doses at respective range of 0.1-2.0 g/L and 0.5-10.0 mM. Higher efficiency of OG oxidation was observed within a wide pH range (3.0-9.0), implying the possibility of applying EDTA-CoFe2O4/PMS process under environmental realistic conditions. Humic acid (HA) at low concentration accelerated the removal of OG; however, a less apparent inhibitive effect was observed at HA addition of 10 mg/L. The kobsvalue was found to decrease slightly from 0.1601 to 0.1274, 0.1248, and 0.1152 min-1with the addition of NO3-, CO32-, and Cl-, respectively, but near-complete removal of OG could still be obtained after 15 min. Both of the sulfate radicals and hydroxyl radicals were produced in the reaction, and sulfate radicals were the dominant according to the scavenging tests and electron paramagnetic resonance (EPR) tests. Finally, a degradation mechanism was proposed, and the stability and reusability of the EDTA-CoFe2O4were evaluated.
Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, 410082, People's Republic of China.
Lin
L
Deng
Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, 410082, People's Republic of China. 369329062@qq.com.
Zhou
Z
Shi
Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, 410082, People's Republic of China.
Zhiyan
Z
Zou
Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, 410082, People's Republic of China.
Shiqing
S
Zhou
D001391:Azo Compounds / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010545:Peroxides / Q000737:chemistry*; D014874:Water Pollutants, Chemical
D001391:Azo Compounds; D005290:Ferric Compounds; D010545:Peroxides; D014874:Water Pollutants, Chemical; C569492:cobalt ferrite; C008710:Orange G; C038288:peroxymonosulfate; D003035:Cobalt; D004492:Edetic Acid
CoFe2O4; Degradation; EDTA; Orange G; Peroxymonosulfate activation