Thesis Format

Integrated Article

Comparison of geosmin and 2-methylisoborneol removal by conventional ozonation and co-treatment of potassium ferrate and peroxymonosulfate

Author

Zhaoran Xin, The University of Western OntarioFollow

Degree

Master of Engineering Science

Program

Chemical and Biochemical Engineering

Supervisor

Rehmann, Lars

2nd Supervisor

Ray, Madhumita

Co-Supervisor

Abstract

Geosmin and 2-methylisoborneol (2-MIB) are two common compounds that cause taste and odor problems in water. This study compares geosmin and 2-MIB removal from water by conventional ozonation, ferrate and peroxymonosulfate (PMS) oxidation processes. The effects of initial O₃ doses, H₂O₂/O₃ ratios, and pH on the removal efficiency of geosmin and 2-MIB were evaluated for ozonation. The addition of H₂O₂ and alkaline condition increased the removal efficiency by ozonation. A Box-Behnken Design was applied to study the influence of ferrate and PMS dosage and pH on the removal of geosmin. It was shown that Ferrate alone was not effective for removing geosmin, but the co-treatment of ferrate and PMS can achieve good geosmin removal.

Summary for Lay Audience

Two of the most common chemicals in drinking water causing unpleasant odors are geosmin and 2-Methylisoborneol (2-MIB). Removal of these two chemicals is challenging for two main reasons. Firstly, the human ability to notice geosmin and 2-MIB is excellent. It means that removal methods are unsuccessful even if only a trace amount of these two chemicals remained after the treatment. Another reason is that geosmin and 2-MIB are resistant to conventional removal processes, including ozonation and absorption. To have better removal results, more potent chemicals are used to oxidize these two compounds. Such removal technologies are called advanced oxidation processes (AOPs). In AOPs, radicals including ·OH, ·SO₄^- or ·FeO₄^- are generated to degrade pollutants.

Firstly, this research examined a traditional AOP method, ozonation. The results showed the addition of ozone was not efficient in the removal of the target pollutants. This was likely due to insufficient ozone dosage and the scavenging effect of methanol (used as a solvent to dissolve geosmin and 2-MIB). Furthermore, the addition of H₂O₂ and an alkaline environment can increase the removal efficiency.

To achieve better removal, the co-treatment of ferrate and peroxymonosulfate (PMS) was studied. Parameters including pH and dosage of PMS and ferrate were investigated. The results showed that this co-treatment process can remove geosmin completely.

Further research could be conducted to investigate the principle of the co-treatment process and the reason for the inefficiency of ferrate oxidation of geosmin and 2-MIB.

Firstly, this research examined a traditional AOP method, ozonation. The results showed the addition of ozone was not efficient in the removal of the target pollutants. This was likely due to insufficient ozone dosage and the scavenging effect of methanol (used as a solvent to dissolve geosmin and 2-MIB). Furthermore, the addition of H₂O₂ and an alkaline environment can increase the removal efficiency.

To achieve better removal, the co-treatment of ferrate and peroxymonosulfate (PMS) was studied. Parameters including pH and dosage of PMS and ferrate were investigated. The results showed that this co-treatment process can remove geosmin completely.

Further research could be conducted to investigate the principle of the co-treatment process and the reason for the inefficiency of ferrate oxidation of geosmin and 2-MIB.

Recommended Citation

Xin, Zhaoran, "Comparison of geosmin and 2-methylisoborneol removal by conventional ozonation and co-treatment of potassium ferrate and peroxymonosulfate" (2021). Electronic Thesis and Dissertation Repository. 8211.
https://ir.lib.uwo.ca/etd/8211