Details

Autor(en) / Beteiligte

• Bae, Sungjun
• Kim, Dongwook
• Lee, Woojin

Titel

Degradation of diclofenac by pyrite catalyzed Fenton oxidation

Ist Teil von

• Applied catalysis. B, Environmental, 2013-05, Vol.134-135, p.93-102

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] ► Pyrite provided proper pH condition (3–4) and appropriate amount of aqueous Fe(II). ► Diclofenac was rapidly degraded (within 120s) in pyrite suspension with H2O2. ► Diclofenac was finally mineralized to HCl and CO2 by pyrite Fenton system. ► HO was identified as a main reactive radical for diclofenac degradation. ► Continuous dissolution of Fe(II) from pyrite surface enhanced diclofenac degradation. We demonstrated that diclofenac can be rapidly and completely oxidized in Fenton reaction system using pyrite as catalyst. The pH of the solution dropped from 5.7 to 4.1–3.2 with addition of different amounts of pyrite (0.5–4.0mM) as Fe(II) concentration increased to 0.07–0.52mM. Complete degradation (100%) of diclofenac was observed by pyrite Fenton system within 120s, while only 65% of diclofenac was removed by classic Fenton system in 180s. Degradation of diclofenac was significantly inhibited (100–51%) by addition of HO scavenger (t-butanol) but not by O2− scavenger (chloroform), indicating that diclofenac was dominantly oxidized by HO produced during pyrite Fenton reaction. It was suggested that continuous dissolution of aqueous Fe(II) by pyrite Fenton reaction supported the complete degradation of diclofenac. The rate of diclofenac degradation increased as pyrite and H2O2 concentrations increased. 2,6-dichlorophenol, 2-chloroaniline, and 2-chlorophenol were detected as major intermediates but they were rapidly degraded in 120s. Chloride ions, ammonium, and total organic carbon measurements confirmed that diclofenac finally degraded to further oxidized forms (organic acids, HCl, and CO2).