Kinetics and pathways of diclofenac degradation by heat-activated persulfate

Abstract

In this study, the degradation of diclofenac (DCF) by heat-activated persulfate (HAP) was investigated.

ABTS as Both Activator and Electron Shuttle to Activate Persulfate for Diclofenac Degradation: Formation and Contributions of ABTS•+, SO4•–, and •OH

“…For pathway II, the formed DP 1 might be dehydrogenated by ABTS •+ and • OH to generate quinone-like product (DP 4 ) resulting from the high electron density of DP 1 . ,, For pathway III, DP 5 was produced via the decarboxylation of DCF with the attack on the phenylacetic acid structure of DCF by ABTS •+ and • OH. DP 5 could be further formylated by • OH to produce DP 6 *, and DP 7 would be produced by the hydroxylation of DP 6 * . However, DP 6 * was not detected in the PDS/ABTS system by LC/Q-TOF/MS, which might be ascribed to the fast transformation of DP 6 * to DP 7 .…”

“…Considering that ABTS •+ , SO 4 •– , and • OH could react with DCF via eqs –, ,, it was reasonable to assume that all of the generated ABTS •+ , SO 4 •– , and • OH made contributions to DCF degradation in the PDS/ABTS system. normalSO 4 • − + DCF → products + normalSO 4 2 − OH • + DCF → products + OH − ABTS • + + DCF → products + ABTS …”

“…DP 5 could be further formylated by • OH to produce DP 6 *, and DP 7 would be produced by the hydroxylation of DP 6 *. 45 However, DP 6 * was not detected in the PDS/ABTS system by LC/Q-TOF/MS, which might be ascribed to the fast transformation of DP 6 * to DP 7 . For pathway IV, DP 8 was derived from the hydroxylation of DP 5 with the attack of • OH on the aromatic ring of DP 5 .…”

“…•− , and • OH could react with DCF via eqs 1−3, 27,30,45 it was reasonable to assume that all of the generated ABTS •+ , SO 4…”

Degradation of ciprofloxacin by persulfate activated with pyrite: mechanism, acidification and tailwater reuse

“…19,20 Usually, PS can be activated to generate SO 4 c − under the conditions of heat, ultraviolet, ultrasound, alkali, and transition metal ions. [21][22][23][24][25] Nevertheless, the most common Fe(II) activated PS was limited by acid conditions and can generate iron sludge. 26,27 Therefore, it is necessary to nd an environmentally friendly activator for SR-AOPs to treat wastewater containing antibiotics.…”