Use of pressurized ozonation for sulfolane degradation in aqueous solutions
Date
2024-09-18
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Abstract
This study investigated the degradation of sulfolane using a pressurized ozonation system in a bench-scale setup, focusing on the effects of operational parameters including system pressures, ozone flow rates, and ozone percentages. The optimal conditions for sulfolane degradation—achieving 90% degradation within 120 minutes—were found to be at a pressure of 20 psi (137.9 kPa), an ozone flow rate of 1 L/min, an ozone percentage of 100%, and an ozone concentration of 3.4 mg/L. The presence of bromide in water led to the formation of bromate, a potential carcinogen, during ozonation. As a result, the effect of initial bromide concentration and system pressure on bromate formation during the ozonation process was examined. The study also evaluated the impact of various inorganic contaminants (HCO3-, Br-, Cl-, SO42-, Mn2+, and Fe3+) on sulfolane degradation. The presence of sulfate slightly improved sulfolane degradation, while others decreased its efficacy. A study on the groundwater samples with pressurized ozonation resulted in 61% sulfolane degradation. Additionally, the degradation of sulfolane using pressurized ozonation under different initial concentrations of 1 mg/L, 20 mg/L, and 100 mg/L was investigated. The lowest concentration had the highest sulfolane degradation. Furthermore, the impact of the addition of various metal ions (Zn²⁺, Mg²⁺, Cu²⁺, Ni²⁺, and Co²⁺) on degradation efficacy demonstrated that zinc and magnesium were the only metal ions that enhanced degradation. Moreover, the combination of activated peroxymonosulfate (PMS) and ozonation was explored, in this regard a few activating agents were studied. Among those that were investigated zinc activation did not considerably enhance sulfolane degradation, while activation with sodium hydroxide (NaOH) achieved near-total degradation. Investigating on concentration change indicated that altering pH was more effective than changing PMS dosage. Finally, the impact of pH changes in pressurized ozonation for reverse osmosis (RO) and tap water matrices confirmed that higher pH levels considerably improved degradation efficacy, achieving up to 98% removal in both water matrices. These findings indicated that optimizing pH and metal ion type is critical for enhancing sulfolane degradation in pressurized ozonation systems.
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Zare, N. (2024). Use of pressurized ozonation for sulfolane degradation in aqueous solutions (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.