Mechanism of the hybrid ozonation-coagulation (HOC)process: Comparison of preformed Al13 polymer and in situ formed Al species

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

Because of the influence of hydrolysed species from Al-based coagulants on coagulation performance, the performance and mechanism of the developed hybrid ozonation-coagulation (HOC)process using AlCl3·6H2O and preformed Al13 as coagulants were investigated in this study, in which ozonation and coagulation occurred simultaneously within a single unit. It was found that the HOC process exhibited higher organic matter removal performance compared with coagulation and the pre-ozonation-coagulation process. It was found that the high ibuprofen (IBP)removal efficiency in the HOC process was mainly attributed to [rad]OH oxidation promoted by in situ formed hydrolysed aluminium species from AlCl3·6H2O and preformed Al13. Furthermore, the surface hydroxyl groups were determined to be the active reaction sites for the HOC process. Due to the higher proportion of surface hydroxyl groups for Al13, the HOC process with preformed Al13 as coagulants (Al13-HOC)exhibited a higher removal performance than that with AlCl3·6H2O as the coagulant (AlCl3-HOC). It was revealed that most of the generated [rad]O2 in the Al13-HOC was adsorbed on the surface of Al13 at different pH values, while a considerably lower proportion of adsorbed [rad]O2 was observed on the surface of in situ formed Al species from AlCl3·6H2O. Nevertheless, low proportions of adsorbed [rad]OH were found on the surfaces of both preformed Al13 and in situ formed Al species, indicating that the [rad]OH oxidation for the removal of organic pollutants occurred primarily in the aqueous phase.

Original languageEnglish
Pages (from-to)262-272
Number of pages11
JournalChemosphere
Volume229
DOIs
StatePublished - Aug 2019
Externally publishedYes

Keywords

  • Hybrid ozonation-coagulation process
  • Hydroxyl radicals
  • Preformed Al
  • Surface hydroxyl groups
  • in situ formed aluminium species

Fingerprint

Dive into the research topics of 'Mechanism of the hybrid ozonation-coagulation (HOC)process: Comparison of preformed Al13 polymer and in situ formed Al species'. Together they form a unique fingerprint.

Cite this