Stephen Mezyk, Ph.D.

Professor

Courses Taught at 娱乐城官网

  • CHEM 111B: General Chemistry (kinetics, equilibria, thermodynamics, electrochemistry, and nuclear chemistry)
  • CHEM 371B: Physical Chemistry: Quantum Mechanics, Spectroscopy, Statistical Mechanics
  • CHEM 373: Physical Chemistry Laboratory
  • CHEM 379: Physical Chemistry for the Biosciences
  • CHEM 572: Graduate Course in Kinetic theory and dynamics

Research Interests

Wastewater Remediation Chemistry

  • Studying free radical kinetic and mechanistic chemistry for remediation of wastewaters for direct potable reuse
  • Radical-based kinetics and efficiencies for removal of pharmaceuticals, drugs and their metabolites, and personal care products from drinking and wastewaters
  • Kinetic modelling of Advanced Oxidation Process treatment of contaminated wastewater
wastewater oxidation/reduction rates
Fig.: measured constants for all the different Advanced Oxidation/Reduction Process radicals (hydrated electrons, hydrogen atoms, hydroxyl radicals, sulfate radicals and superoxide) with the chlorinated and brominated acetonitriles of the associated study.  

Nuclear Chemistry

  • Radical kinetics, degradation and extraction efficiency studies of the steady-state radiolysis of organic ligand systems used for transuranic ion extractions for waste fuel recycling performed in both the aqueous and organic phases
  • Radiation-induced degradation of metal ion-extraction ligands and solvents used in nuclear chemistry
  • Thermal and radiation-induced actinide chemistry in higher oxidation states
  • Stopped-flow kinetic and thermodynamic measurements of f-element ion complexations by organic ligands in both aqueous and organic phases
  • Kinetic modelling of thermal and radiation-induced chemistry of the higher oxidation states of actinides in the acidic aqueous phase
decay kinetics
Fig.: Top plot: Decay kinetics for the radical cation reaction with the HEH[EHP] ligand dimers in n-dodecane at room temperature.
Inset plot: second-order rate constant measurement determined from measured decay kinetics for this reaction.
Bottom plot: summary of all measured reaction rate constants for lanthanide ions and one actinide, americium, complexed with HEH[EHP] in dodecane. Solid line shows excellent agreement with predictions of theoretical reaction volumes for these rate constants.

Chemical Carcinogenesis Chemistry

  • Free-radical kinetics and mechanisms in the redox chemistry of carcinogen activation
  • Mechanisms of redox chemistry involved in chemical carcinogenesis
  • Metal ion-ligand biochemical systems for use in cancer treatment therapies
  • Radical reaction induced redox chemistry of complexed metal ions in aqueous solution under physiological conditions
advanced water purification system and determination system
Fig.: Left: The advanced water purification system at the Orange County Water District in Fountain Valley, California. Wastewater is first purified through a Reverse Osmosis membrane before being treated by a 254 nm UV light system in an Advanced Oxidation Process where methyl nitrate is formed.
Right: methyl nitrate determination system developed in this study. Treatment of the generated methyl nitrate by 222 nm photochemical conversion to produce peroxynitrate which in the presence of luminol gives an absorbing product that allows us to quantify concentrations.

Nanoplastics Chemistry

  • Free radical based removal of plastic waste from water systems
  • Determining rate constants and reaction mechanisms for reactions of reducing and oxidizing radicals with plastics and components in various quality waters
macroplastic particles before and after being solubilized in water
Fig.: Top: Real-world macroplastic particles found in the environment before and after being solubilized in water.
Bottom plot: Raman spectrum of the generated polyethylene microplastics.

Selected Publications

* indicates students

Wastewater

  • Mezyk, S.P.*; Rogalski, M.H.; Dang, A.N.; Bartels, D.M.; Hardison, D.R.; Cooper, W.J., Radical Treatment of Haloacetonitriles in Aqueous Solution: A Kinetics Study, ACS Env. Sci. Technol. Water, 2025
  • Fennell, B.D.; Fowler, D.; Mezyk, S.P.; McKay, G., Reactivity of dissolved organic matter with the hydrated electron: Implications for treatment of chemical contaminants in water with advanced reduction processes. Env. Sci. Technol., 57, 7634-7643, (2023).
  • Fennell, B.D.*; Mezyk, S.P.; McKay, G., Critical Review of UV-Advanced Reduction Processes for the Treatment of Contaminants in Water. American Chemical Society Environmental Au 2, 178-205, (2022).

Nuclear Chemistry

  • Rogalski, M.H.; Dang, A.N.; Mezyk, S.P.*, Evaluation of the Arrhenius behavior of n-dodecane radical cation (RH鈼+) reactivity with lanthanide ion-complexed N,N,N鈥,N鈥-tetraoctyldiglycolamide (TODGA). Phys. Chem. Chem. Phys. 27, 1960-1967, (2025).
  • Kynman, A.E.*; Dang, A.N.; Grimes, T.S.; Mezyk, S.P.; Wilbanks, J.R.; Zarzana, C.A.; Deokar, R.G.; Cook, A.R.; Boglaienko, D.; Hall, G.B.; Horne, G.P.*, Influence of metal ion complexation on the radiolytic longevity of butyramide extractants under direct dissolution process conditions. ACS Omega, 10, 8, 7822-7830, (2025).
  • Mezyk, S.P.*; Baxter, M.; Celis-Baros, C.; Grimes, T.S.; Zalupski, P.R.; Rae, C.; Zarzana, C.A.; Cook, A.R.; Horne, G.P.*, Effect of f-element Complexation on the Radiolysis of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). Dalton Trans. 53, 6881-6891, (2024).

Nanoplastics

  • Peller, J.R.*; Durlam, N.; Flaherty, Y.; Valicevic, A.; Davis, C.M.; Watson, S.; Tournebise, J.E.; Medina-Garcia, J.A.; Dadmun, M.; Mezyk, S.P., Incognito forms of polyethylene in water: changes in molecular vibrations of small micro and nanoplastics. Sci, Tot. Environ, 968, 178923 (2025).
  • Peller, J.R.; Mezyk, S.P.; Shidler, S.; Castleman, J.*; Kaiser, S.*; Faulkner, R.F.*; Pilgrim, C.D.; Wilson, A.*; Martens, S.*; Horne, G.P., Facile nanoplastics formation from macro and microplastics in aqueous media. Env. Pollut., 120171, 2022.

Chemical Carcinogensis

  • Kodamatani, H.; Sugihara, K.; Mezyk, S.P.; Ishida, K.P.; Roback, S.L., Plumlee, M.H., Methyl nitrate as byproduct in advanced water treatment systems: Novel liquid chromatographic determination method and cause of formation. Chemosphere. 140308, (2023).

Education History

  • Ph.D., Chemistry, University of Melbourne, Australia, 1989

Work Experience

  • 08/2009 - present: Professor, Department of Chemistry and Biochemistry, CSU Long Beach, CA
  • 03/2025 - present: Joint Appointment, Idaho National Laboratory, Center for Radiation Chemistry Research
  • 05/1986 - present: Visiting Scholar Appointment, Radiation Laboratory, Notre Dame, IN
  • 06/2002 - present: Visiting Appointment, Brookhaven National Laboratory, Long Island, NY