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

Magnetic nanocomposite β-alaninediacetic acid-modified Fe 3 O 4 (β-ADA@Fe 3 O 4 ) was prepared, characterized and evaluated to activate peroxymonosulfate (PMS) for improved degradation of sulfadiazine (SD). The results reveal that β-ADA@Fe 3 O 4 express more efficient catalytic activity in PMS inducement compared with Fe 3 O 4 , and the observed pseudo first rate constant ( k obs ) of SD degradation is enhanced from 1.05 × 10 −2 to 7.02 × 10 −2  min −1 when Fe 3 O 4 is replaced by β-ADA@Fe 3 O 4 . The highest removal rate 54.0% occurs when [PMS] 0 and m(β-ADA@Fe 3 O 4 ) 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 (SO 4 − ) are distinguished in system by scavenging experiments and electron paramagnetic resonance (EPR) tests. Results point that β-ADA would significantly promote the circulation of Fe 2+ -Fe 3+ on the surface of β-ADA@Fe 3 O 4 , producing more radicals ( OH, SO 4 − ). The findings herein imply that β-ADA@Fe 3 O 4 is an efficient and green catalyst in activation of peroxymonosulfate under neutral environment.