US EPA

3230226 

Journal Article 

Reaction pathway and oxidation mechanisms of dibutyl phthalate by persulfate activated with zero-valent iron 

Li, H; Wan, J; Ma, Y; Wang, Y 

2016 

Yes 

Science of the Total Environment
ISSN: 0048-9697
EISSN: 1879-1026 

562 

889-897 

English 

27125682 

10.1016/j.scitotenv.2016.04.093 

WOS:000377372400086 

is supplemented by 3479712 - Supplementary material

This study investigated reaction pathway and oxidation mechanisms of dibutyl phthalate (DBP) by persulfate (PS) activated with zero-valent iron (ZVI). The DBP degradation was studied at three pH values (acidic, neutral and basic) in the presence of different organic scavengers. Using a chemical probe method, both sulfate radical (SO4(-)) and hydroxyl radical (·OH) were found to be primary oxidants at pH3.0 and pH7.0, respectively while ·OH was the major specie to oxidize DBP at pH11.0. A similar result was found in an experiment of Electron Spin Resonance spin-trapping where in addition to OH, superoxide radical (O2(-)) was detected at pH11.0. The transformation of degradation products including dimethyl phthalate (DMP), diethyl phthalate (DEP), phthalic anhydride, and acetophenone exhibited diverse variation during the reaction processes. The phthalic anhydride concentration appeared to be maximum at all pHs. Another eleven intermediate products were also found at pH3.0 by GC-MS and HPLC analysis, and their degradation mechanisms and pathways were proposed. It was suggested that dealkylation, hydroxylation, decarboxylation and hydrogen extraction were the dominant degradation mechanisms of DBP at pH3.0.