Degradation of azo dye with activated peroxygens: When zero-valent iron meets chloride

  • Zhaohui Wang*
  • , Luoyan Ai
  • , Ying Huang
  • , Juekai Zhang
  • , Sitong Li
  • , Jiawei Chen
  • , Fei Yang
  • *Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

59 Scopus citations

Abstract

Degradation of acid orange 7 (AO7) by Fe-based Advance Oxidation Process (AOPs) with common peroxygens, persulfate (PS), peroxymonosulfate (PMS) and hydrogen peroxide (H2O2), was investigated, in which sulfate radicals (SO4-) and/or hydroxyl radicals (OH) are powerful oxidizing species. The effects of Fe dosage, peroxygen concentration, initial pH and the presence of chloride on the degradation of AO7 were examined. The AO7 degradation efficiencies by four systems, including Fe, Fe/H2O2, Fe/PMS and Fe/PS were compared. AO7 degradation rate by Fe activated AOPs in descending order is H2O2 ≧ PS > PMS. Increasing acidity and iron dosage favored a rapid degradation of AO7. The presence of chloride greatly inhibited dye removal in Fe/H2O2 and Fe/PS systems, whilst accelerated dye degradation was observed in the Fe/PMS system. In contrast, mineralization of AO7 in the Fe/PMS/Cl- system was minimal, because of formation of lots of refractory chlorinated phenols as identified by GC-MS. These findings are useful for selecting the most appropriate technology for textile wastewater treatment, depending on the wastewater constituents and pH.

Original languageEnglish
Pages (from-to)30941-30948
Number of pages8
JournalRSC Advances
Volume7
Issue number49
DOIs
StatePublished - 2017
Externally publishedYes

Fingerprint

Dive into the research topics of 'Degradation of azo dye with activated peroxygens: When zero-valent iron meets chloride'. Together they form a unique fingerprint.

Cite this