Removal of 1,4-Dioxane and Volatile Organic Compounds from Groundwater Using Ozone-Based Advanced Oxidation Process

ABSTRACT

Ozone and ozone/peroxide processes were evaluated for the removal of 1,4-dioxane from laboratory water and site groundwater. The effect of process parameters such as solution pH and dosage of peroxide was studied. Ozone alone was not very effective in removing 1,4-dioxane from water (≤ 20% removal). Enhanced oxidation of 1,4-dioxane was achieved by increasing the solution pH or by adding peroxide at neutral pH. Pseudo–first-order rate constants were calculated for the removal of 1,4-dioxane using ozone. Correlations were developed for the consumption of ozone per 1,4-dioxane removed. Acidic and neutral pH conditions resulted in higher consumption of ozone per dioxane removed. Basic solution pH and presence of hydrogen peroxide enhanced the dioxane removal, which resulted in lower consumption of ozone per dioxane removed. Following the lab study, ozonation was used for the remediation of site groundwater contaminated with 1,4-dioxane and chlorinated volatile organics. Presence of 5 mg/L of hydrogen peroxide during ozonation resulted in simultaneous removal of 1,4-dioxane and volatile organics from groundwater to target levels. For the AOP process, removal kinetics was approximately 50% slower in groundwater compared to the lab DI water.

KEYWORDS:

• Ozone
• 4-Dioxane
• AOP
• Groundwater Remediation
• Hydrogen Peroxide
• Volatile Organic Compounds

Acknowledgments

The laboratory assistance provided by Tony Singh and Marianne Curran is acknowledged.

Funding

The NSF – Water and Environmental Technology (WET) Center funded this project. Opinions, findings and conclusions expressed in this article are those of the authors and do not necessarily reflect the views of NSF-WET Center or Temple University.

Additional information

Funding

The NSF – Water and Environmental Technology (WET) Center funded this project. Opinions, findings and conclusions expressed in this article are those of the authors and do not necessarily reflect the views of NSF-WET Center or Temple University.