ORIGINAL ARTICLE Kinetics of ozonation and mass transfer of PharmaceuticalsDegraded by ozone fine bubbles in a plant prototype Surabhi Patel 1 & Rohit Agarwal 1 & Subrata Kumar Majumder 1 & Papita Das 2 & Pallab Ghosh 1 Received: 14 September 2018 /Accepted: 25 July 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The kinetics of degradation of pharmaceutical drugs is studied by ozonation in a fine bubble system. In the present experimental work, fine bubbles of ozone were used for degradation of pharmaceutical drugs soluble in water. The ozonation of pharmaceutical drugs by ozone bubbles was found to be very effective at high pH and high ozone flow rates. The apparent reaction rate constant was estimated at different pH of the solution. The axial variation of ozone concentration in solution in the reactor is analyzed by dispersion model. The volumetric mass transfer coefficients based on the ozonation of pharmaceutical drugs by fine bubble based are also enunciated in this present work. The results may be useful for removal of drug waste in water treatment process by advanced oxidation techniques. Notations a i Interfacial area per volume of reactor (m 2 m -3 ) C G Concentration of ozone in the gas phase (mM or mg L -1 ) C L Concentration of dissolved ozone in aqueous phase at time t (mM or mg L -1 ) c * O 3 Equilibrium ozone concentration in aqueous phase (mM or mg L -1 ) c ss Steady state ozone concentration in aqueous phase at t→∞ (mM or mg L -1 ) D Molecular diffusion coefficient in the film (m -2 s -1 ) D a Damkohler number (-) H Henry’ s law constant (Pa mol fraction -1 ) k Reaction rate constant (M -1 s -1 ) k D First-order decomposition rate constant of ozone (s -1 ) k L a Volumetric mass transfer coefficient of ozone (s -1 ) k app Pseudo-First-order reaction rate constant (s -1 ) K OH Rate constants with OH radicals (M -1 s -1 ) K O 3 Rate constants with O 3 (M -1 s -1 ) M Molecular weight of water (kg mol -1 ) L Length of the reactor (m) [NPX] Concentration of NPX at time t (mM or mg L -1 ) [NPX] o Initial concentration of NPX (mM or mg L -1 ) [O 3 ] Ozone concentration at time t(mM or mg L -1 ) [O 3 ]* Saturated ozone concentration (mM or mg L -1 ) p Partial pressure of ozone in the gas phase (Pa) P Total pressure of the system (N m -2 ) [P] Concentration of pharmaceutical drug at time t (mM or mg L -1 ) [P] 0 Initial concentration of pharmaceutical drug (mM or mg L -1 ) P e Peclet number (-) Q Volumetric flow rate (m 3 s -1 ) R Gas constant (J mol -1 K -1 ) Re Reynolds number t Time (s) T Temperature (K) V Reactor volume (m 3 ) X N Conversion of NPX Greek Letters β Dimensionless number (-) ρ Density of water (kg m -3 ) σ Surface tension of the liquid (N m -1 ) ε g Fractional gas holdup γ Dimensionless number (-) δ Thickness of diffusion film (m) ζ Dimensionless number (-) ξ Dimensionless number (-) * Surabhi Patel p.surabhi@iitg.ac.in * Subrata Kumar Majumder skmaju@iitg.ac.in 1 Chemical Engineering Department, Indian Institute of Technology Guwahati, Guwahati, Assam, India 2 Chemical Engineering Department, Jadavpur University, Kolkata 700032, India Heat and Mass Transfer https://doi.org/10.1007/s00231-019-02718-7