Enhanced degradation of sulfadiazine by novel β-alaninediacetic acid-modified Fe3O4 nanocomposite coupled with peroxymonosulfate

Magnetic nanocomposite β-alaninediacetic acid-modified Fe3O4 (β-ADA@Fe3O4) was prepared, characterized and evaluated to activate peroxymonosulfate (PMS) for improved degradation of sulfadiazine (SD). The results reveal that β-ADA@Fe3O4 express more efficient catalytic activity in PMS inducement compared with Fe3O4, and the observed pseudo first rate constant (kobs) of SD degradation is enhanced from 1.05 × 10-2 to 7.02 × 10-2 min-1 when Fe3O4 is replaced by β-ADA@Fe3O4. The highest removal rate 54.0% occurs when [PMS]0 and m(β-ADA@Fe3O4)0 was 0.3 mM and 0.8 g/L at neutral pH. High intensity of hydroxyl radicals (OH) and relatively low intensity of sulfate radicals (SO4-) are distinguished in system by scavenging experiments and electron paramagnetic resonance (EPR) tests. Results point that β-ADA would significantly promote the circulation of Fe2+-Fe3+ on the surface of β-ADA@Fe3O4, producing more radicals (OH, SO4-). The findings herein imply that β-ADA@Fe3O4 is an efficient and green catalyst in activation of peroxymonosulfate under neutral environment.