Bicarbonate-activated persulfate oxidation of acetaminophen

Area of Science:

• Environmental Chemistry
• Water Remediation Science

Background:

• Persulfate (PS) is a common oxidant for in situ chemical remediation of contaminated groundwater.
• Understanding PS activation mechanisms is crucial for effective subsurface remediation.

Purpose of the Study:

• To investigate the activation of persulfate by bicarbonate for groundwater remediation.
• To elucidate the transformation pathways of acetaminophen in the PS/bicarbonate system.

Main Methods:

• Utilized acetaminophen as a probe compound to study PS/bicarbonate reactivity.
• Employed radical scavenger tests and furfuryl alcohol as a probe for reactive oxygen species.
• Quantified singlet oxygen generation using kinetic solvent isotopic effect in D2O.

Main Results:

• Acetaminophen transformation followed pseudo-first-order kinetics with respect to acetaminophen and PS concentrations.
• Singlet oxygen (1O2) was generated but primarily contributed to furfuryl alcohol transformation, not acetaminophen.
• Peroxymonocarbonate (HCO4-) was identified as the main species responsible for acetaminophen transformation via one-electron abstraction.

Conclusions:

• Bicarbonate activation of persulfate generates peroxymonocarbonate, which is key for acetaminophen remediation.
• The findings highlight the significance of bicarbonate in subsurface persulfate oxidation processes.
• This research provides fundamental insights into persulfate oxidation mechanisms in groundwater environments.