ABSTRACT
In order to overcome the shortcomings in the traditional Fenton process, Fe(III)-EDDS-activated persulfate advanced oxidation process under irradiation is carried out as a promising technology. The photodegradation of sulfadiazine (SD) in Fe(III)-EDDS-activated persulfate system was investigated in this paper. The results showed that SD could be effectively degraded in Fe(III)-EDDS//hv system. The effects of Fe(III):EDDS molar ratio, the concentration of Fe(III)-EDDS, and the concentration of
on SD degradation were explored. At neutral pH, when Fe(III):EDDS = 1:1, Fe(III)-EDDS = 0.1 mM,
= 1.5 mM, the best SD degradation was achieved. The experiment of external influence factors showed that the degradation of SD could be obviously inhibited by the presence of
,
, whereas the degradation of SD was almost unaffected by the addition ofCl−. The degradation of SD could be slightly inhibited by the presence of humic acid and NO3−. The effect of pH on SD degradation was investigated, and SD could be degraded effectively in the pH range of 3–9. ESR proved that 1O2, ·OH,
, and O2− were produced in the process.
and ·OH were identified as the main radicals while O2·− also played non-ignorable role. Eleven intermediate products of SD were analysed. The C = N, S–N, and S–C bonds of SD were attacked by radicals firstly, leading to a series of reactions that eventually resulted in the destruction of SD molecules and the formation of small organic molecules.
GRAPHICAL ABSTRACT
![](/cms/asset/0604ed79-76b1-4cd1-bbff-5a6d041132cc/tent_a_2064238_uf0001_oc.jpg)
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
Corresponding author would provide data on a reasonable request.