Rate Equations Research Articles

Cell seeding dynamics in a porous scaffold material designed for meniscus tissue regeneration

AbstractWe study the dynamics of a seeding experiment where a fibrous scaffold material is colonized by two types of cell populations. The specific application that we have in mind is related to the idea of meniscus tissue regeneration. In order to support the development of a promising replacement material, we discuss certain rate equations for the densities of human mesenchymal stem cells and chondrocytes and for the production of collagen‐containing extracellular matrix. For qualitative studies, we start with a system of ordinary differential equations and refine then the model to include spatial effects of the underlying nonwoven scaffold structure. Numerical experiments as well as a complete set of parameters for future benchmarking are provided.

Synthesis of dihydrocarvone over dendritic ZSM-5 Zeolite: A comprehensive study of experimental, kinetics, and computational insights

This study explores the isomerization of limonene-1,2-epoxide (LE) from kinetic and mechanistic viewpoints, using a dendritic ZSM-5 zeolite (d-ZSM-5) as a highly selective catalyst for the formation of dihydrocarvone (DHC) in the form of diastereoisomers (cis + trans). Ethyl acetate, a green solvent, was used at mild reaction temperatures (50–––70 °C). DHC, which can also be extracted from caraway oil, is widely used as an intermediate for epoxylactone production and as a constituent in flavors and perfumes. Kinetic modeling of LE isomerization was performed using a reaction network with eight parallel reactions and the corresponding rate equations, derived from the assumption of the rate-limiting surface reactions. The large standard errors in the statistical results of some kinetic parameters of the initial data fitting suggested that three of those reactions can be neglected to describe the kinetic model more accurately. This refinement resulted in standard errors in the kinetic parameters lower than ca. 11 %, confirming the statistical reliability of the modified kinetic model. Activation energies of 41.1 and 162 kJ/mol were estimated for the formation of cis-DHC and trans-DHC, respectively. Density Functional Theory (DFT) calculations revealed the preferred pathway for both cis and trans-LE conversion to DHC and carveol. The rate-determining step, carbocation formation (ΔEact = 234 kJ/mol), precedes near-instantaneous dihydrocarvone formation under the studied conditions.

Exploring tubular steady‐state laminar flow reactors with orthogonal collocation

AbstractThe laminar flow reactor (LFR) is one of the most comprehensive problems in chemical reaction engineering, as its modeling involves mass, heat, and momentum conservation equations coupled with chemical reaction rate equations. It is relatively easy to grasp its basic operation, but the solution of the problem is far from trivial. Although there are analytical solutions that simplify the problem, students and tutors must use efficient numerical strategies to appropriately solve some LFR problems. In the present investigation, we solve several different cases of two‐dimensional cylindrical LFR, beginning with the isothermal case, as a benchmark. Calculations were performed using the Chebyshev orthogonal collocation technique by custom scripts in Scilab, Mathematica©, and Matlab®, and were compared with solutions available from the ECRE Version of COMSOL®, which was used as the reference, as well as available analytical solutions in the literature. After analyzing the case of the isothermal LFR with Newtonian fluid, we explored non‐Newtonian fluids, including Carreau and Bingham fluids, whose LFR results are not available in the preceding literature. For Newtonian fluids, besides (a) the isothermal case, we also explore other three nonisothermal design cases: (b) cooling jacket with a fixed heat exchange coefficient at the wall, (c) adiabatic operation, (d) nonisothermal LFR with isothermal wall. Through a performance criterion, the different operation models are compared and we show that nonisothermal design cases perform better than the isothermal case. Computation times, for different scenarios, are quite short and taking 25 nodal points or more suffice for an accurate and timely solution of the more complex problem Case (b). The numerical modeling approach is useful from a pedagogical standpoint, as one can compare numerical results with classical assumptions, and progress from a more restrictive conceptual model (segregated flow) to an array of different kinds of operation with the LFR in which one needs to consider diffusion and temperature distribution.

CoOMBE: A suite of open-source programs for the integration of the optical Bloch equations and Maxwell-Bloch equations

The programs described in this article and distributed with it aim (1) at integrating the optical Bloch equations governing the time evolution of the density matrix representing the quantum state of an atomic system driven by laser or microwave fields, and (2) at integrating the 1D Maxwell-Bloch equations for one or two laser fields co-propagating in an atomic vapour. The rotating wave approximation is assumed. These programs can also be used for more general quantum dynamical systems governed by the Lindblad master equation. They are written in Fortran 90; however, their use does not require any knowledge of Fortran programming. Methods for solving the optical Bloch equations in the rate equations limit, for calculating the steady-state density matrix and for formulating the optical Bloch equations in the weak probe approximation are also described. Program summaryProgram Title: CoOMBECPC Library link to program files:https://doi.org/10.17632/5wsg9d52dk.1Developers' repository link:https://github.com/durham-qlm/CoOMBELicensing provisions: GPLv3Programming language: Fortran 90Nature of problem: The present programs can be used for the following operations: (1) Integrating the optical-Bloch equations within the rotating wave approximation for a multi-state atomic system. At the choice of the user, the calculation will return either the time-dependent density matrix at given times or the density matrix in the long time limit if the system evolves into a steady state in that limit. The calculation can be done with or without averaging over the thermal velocity distribution of the atoms. The number of atomic states which can be included in the calculation is limited only by the CPU time available and possibly by memory requirements. An arbitrarily large number of laser or microwave fields can be included in the calculation if these fields are all CW. This number is currently limited to one or two for fields that are not all CW. The calculation can be done in the weak probe approximation, or in the rate equations approximation, or without assuming either of these two approximations. Calculating refractive indexes, absorption coefficients and complex susceptibilities is also possible. (2) Integrating the 1D Maxwell-Bloch equations in the slowly varying envelope approximation for one or two fields co-propagating in a single-species atomic vapour. Although geared towards the case of atoms interacting with laser fields, this code can also be used for more general quantum systems with similar equations of motion (e.g., molecular systems, spin systems, etc.).Solution method: The Lindblad master equation is expressed as a system of homogeneous first order linear differential equations, which are transformed as required and solved to obtain the density matrix representing the state of the atomic system. A variety of methods are offered to this end. The same approach is also used in the calculation of the polarisation of the medium when integrating the Maxwell-Bloch equations. The latter are integrated over space using predictor-corrector methods. The library includes a general driving program making it possible to use these codes without additional program development. The distribution also includes examples of the use of a container for running these programs without a pre-installed Fortran compiler.

Quantitative and mechanistic elucidation of the reactive oxygen species for effective sulfamethoxazole removal in heterogeneous peroxymonosulfate activated by MOFs-derived cladding structure CoZn/NC@UiO

In cobalt-based catalyst/peroxymonosulfate (PMS) systems, the key issues are the leaching of metals and the stability of catalysts. In this study, a NH2-UiO-66 cladded CoZn/NC catalyst was synthesized for efficient degradation of sulfamethoxazole (SMX) using activated PMS. The removal efficiency of SMX could achieve 100 % within 30 min. The leaching of Co2+ was inhibited to 0.05 ppm and the anti-interference and cyclic stability of the catalyst were enhanced by the NH2-UiO-66 shell. In addition, the quenching experiment, electron paramagnetic resonance (EPR) technique and probe experiment were used to analyze the reactive oxygen species (ROSs) qualitatively and quantitatively. The findings demonstrated that singlet oxygen (1O2) had the highest steady-state and cumulative concentration. However, 1O2 could only participate in the degradation of SMX through single electron transfer or addition reaction, resulting in a lower second-order rate constant of the SMX reaction with 1O2. Sulfate radical (SO4−) contributed the most to the degradation of SMX due to the high reactivity of the sulfonamide structure in SMX to SO4−. Finally, possible pathways for SMX degradation were proposed. The two primary mechanisms of SMX degradation were S-N cleavage and amino hydroxylation/oxidation. The toxicity of most of the intermediates was less than that of SMX through ecological structure–activity relationship analysis. Overall, a novel approach to synthesize low leaching and efficient cobalt based catalyst was put forward, and the activation mechanism of PMS was also revealed.

Resilience of weighted networks with dynamical behavior against multi-node removal.

In many real-world networks, interactions between nodes are weighted to reflect their strength, such as predator-prey interactions in the ecological network and passenger numbers in airline networks. These weighted networks are prone to cascading effects caused by minor perturbations, which can lead to catastrophic outcomes. This vulnerability highlights the importance of studying weighted network resilience to prevent system collapses. However, due to many variables and weight parameters coupled together, predicting the behavior of such a system governed by a multi-dimensional rate equation is challenging. To address this, we propose a dimension reduction technique that simplifies a multi-dimensional system into a one-dimensional state space. We applied this methodology to explore the impact of weights on the resilience of four dynamics whose weights are assigned by three weight assignment methods. The four dynamical systems are the biochemical dynamical system (B), the epidemic dynamical system (E), the regulatory dynamical system (R), and the birth-death dynamical system (BD). The results show that regardless of the weight distribution, for B, the weights are negatively correlated with the activities of the network, while for E, R, and BD, there is a positive correlation between the weights and the activities of the network. Interestingly, for B, R, and BD, the change in the weights of the system has little impact on the resilience of the system. However, for the E system, the greater the weights the more resilient the system. This study not only simplifies the complexity inherent in weighted networks but also enhances our understanding of their resilience and response to perturbations.

Physiologically based in vitro – In vivo correlation of modified release oral formulations with non-linear intestinal absorption: A case study using mirabegron

Establishing an in vitro – in vivo correlation (IVIVC) for oral modified release (MR) formulations would make it possible to substitute an in vitro dissolution test for human bioequivalence (BE) studies when changing the formulation or manufacturing methods. However, the number of IVIVC applications and approvals are reportedly low. One of the main reasons for failure to obtain IVIVCs using conventional methodologies may be the lack of consideration of the dissolution and absorption mechanisms of drugs in the physiological environment. In particular, it is difficult to obtain IVIVC using conventional methodologies for drugs with non-linear absorption processes. Therefore, the aim of the present study was to develop a physiologically based biopharmaceutics model (PBBM) that enables Level A IVIVCs for mirabegron MR formulations with non-linear absorption characteristics.Using human pharmacokinetic (PK) data for immediate-release formulations of mirabegron, the luminal drug concentration-dependent membrane permeation coefficient was calculated through curve fitting. The membrane permeation coefficient data were then applied to the human PK data of the MR formulations to estimate the in vivo dissolution rate by curve fitting. It was assumed that in vivo dissolution could be described using a zero-order rate equation. Furthermore, a Levy plot was generated using the estimated in vivo dissolution rate and the in vitro dissolution rate obtained from the literature. Finally, the dissolution rate of the MR formulations from the Levy plot was applied to the PBBM to predict the oral PK of the mirabegron MR formulations.This PB-IVIVC approach successfully generated linear Levy plots with slopes of almost 1.0 for MR formulations with different dose strengths and dissolution rates. The Cmax values of the MR formulations were accurately predicted using this approach, whereas the prediction errors for AUC exceeded the Level A IVIVC criteria. This can be attributed to the incomplete description of colonic absorption in the current PBBM.

Modeling plasticity-mediated void growth at the single crystal scale: A physics-informed machine learning approach

Modeling the evolution of voids during plastic flow as well as their effects on plastic dissipation is critical for both component manufacturing and lifetime estimation purposes. To this end, we propose a rate-dependent constitutive model to homogenize the effects of semi-randomly distributed voids on single crystal plasticity whilst capturing void interaction and plastic anisotropy. The present work focuses on the case of face centered cubic crystals to introduce an anisotropic gauge function applicable within the crystal plasticity formalism. The approach combines analytical methods to describe the micromechanics of the system in combination with symbolic regression to capture analytically intractable mechanisms from data. The hybrid framework uses a physics-informed genetic programming-based symbolic regression algorithm to solve a multiform optimization problem simultaneously producing a new gauge function and a new strain rate equation. This is also a multi-objective optimization problem with many competing objectives. A new search and selection step is introduced to the genetic algorithm that promotes convergence toward a global solution that better satisfies all the objectives. Overall, the symbolic equations produced leverage data-driven methods to achieve greater accuracy than comparable alternatives on an analytically intractable problem while maintaining model transparency.

A covariant formulation for finite strain modelling of orthotropic elasticity and orthotropic plasticity with plasticity-induced evolution of orthotropy: Application to natural fibres

We introduce a rate-independent model for orthotropic elastic and orthotropic plastic material behaviour in a hyper-elasto-plastic framework at finite strains. The model is based on the postulate of covariance and does not rely on a multiplicative decomposition of the deformation gradient. Furthermore, a plastic-deformation-induced evolution of orthotropy is considered, similar to the notion of plastic spin. We propose that the orthotropic strain energy function and the orthotropic yield criterion are guided by identical structural tensors that evolve with plasticity. The modelled material behaviour is significant for natural fibres such as flax, hemp, or pulp fibres. Our formulation has three findings. Firstly, the covariant formulation of plasticity provides rate equations for the plastic variables and the structural tensors suitable for reproducing stress–strain diagrams of natural fibres. Secondly, the introduction of plastic-deformation-induced evolution of orthotropy in the proposed covariant setting results in a non-associative plasticity algorithm. Thirdly, the covariant setting allows the incorporation of suitable constitutive equations for the structural tensors to evolve orthotropy. The latter successfully models the stiffness increase in stress–strain diagrams of cyclic tensile tests of natural fibres.

Frequency pushing and pulling in semiconductor lasers subject to optical frequency comb injection

We theoretically investigate the frequency shift of a free-running semiconductor laser when optically injected by an optical frequency comb. By numerical integration of the laser rate equations, we have identified two types of frequency shifts, frequency pulling, and frequency pushing. The free-running slave laser seems to switch between pulling and pushing in a regular manner. We have systematically determined the dependence of these shifts on comb parameters, including comb spacing and number of lines. We have found that the occurring frequency pushing seems to be almost independent of comb signals and comb spacing, while in contrast, the frequency pulling shows weak dependence on comb signals but largely affected by comb spacing. We have also shown that carrier density dynamic is the origine of these phenomena.

Coupled Adsorption/Precipitation (Γ/∏) Modelling of Scale Inhibitor Transport in Porous Media Using the Coupled Isotherm, AΓ∏(c)

Scale inhibitor (SI) “squeeze” treatments are widely used operations in production assurance to prevent inorganic scales as one of the main flow assurance problems. In these treatments, a high concentration SI slug is injected (“squeezed”) into the porous medium, retained in the formation rock, and is gradually produced back at relatively small concentrations that can prevent (or significantly reduce) scale formation. The retention of SI in the formation is governed by coupled mechanisms of adsorption (Γ) and precipitation (∏) of SI species in the system. To design such SI treatments in an optimized manner, it is important to have good mathematical models of both the transport and the coupled interactions of adsorption/precipitation (Γ/∏) processes.In this study, a 1D advection-dispersion-reaction transport model has been developed, considering the coupled Γ/∏ retention processes, and it is used to model linear core flood systems. The parameters for the equilibrium Γ/∏ model can be derived from the routine bulk SI “apparent adsorption” tests that are usually conducted before any treatments. From previous works, equilibrium adsorption isotherm, Γ(c), is used to describe the adsorption behavior in such systems. However, although the precipitation kinetics are “fast” (almost at equilibrium), the kinetics of SI dissolution are “slow” and is therefore modelled by a kinetic rate law. From the derived dimensionless form of the transport-Γ/∏ model equations, it is shown that the system is governed by 4 dimensionless numbers, NA, NP, NPe and NDa, which are the adsorption number, the precipitation number, the Peclet number, and the Damköhler number, respectively. The shape of the adsorption isotherm also plays a very important part in the extent and form of the effluent SI returns from the linear system.The developed model was then employed to carry out a series of sensitivity calculations relating to coupled adsorption/precipitation (Γ/∏) processes. Both equilibrium and kinetic SI precipitation were modelled coupled with the equilibrium SI adsorption, and the effect of these processes on the form and extent of the SI effluents was assessed. A range of sensitivities was then carried out to determine the effect of a wide range of parameters, including the effects of flow rate and shut-in periods on the kinetic dissolution effluent behavior. The findings from this work present the most clear explanation to date of why and how “precipitation squeezes” can greatly extend squeeze lifetime. A novel feature of this analysis is to show how the role of precipitation and adsorption changes over the various stages of the return effluent by developing plots of the %SI adsorbed on the rock, in the precipitate, and the mobile fluid phase.

Oxidative transformation of methionine by pyridinium chlorochromate in aqueous DMF medium: A kinetic study

The Kinetics of Oxidative transformation of Methionine by pyridinium chlorochromate in aqueous DMF medium, containing perchloric acid has been studied. The rate of reaction was found to be of first order dependence on PCC, Methionine, and H+ ion Concentration. Michaelis–Menten type kinetics is observed respect to substrate. The increase in the rate of reaction with increase in acidity indicates the involvement of a protonated chromium(VI) species in the rate-determining step. The product of oxidation has been identified as methionine sulfoxide. The rate of reaction increased with increase in dielectric constant of the reaction medium. The plots of logkobs versus (D-1) / (2D+1) are non linear Indicating that there is an involvement of positive ion-dipole in the rate determining step. The activation parameters have been evaluated. On the basis of the experimental findings, a suitable mechanism and rate law has been proposed.

An accurate and efficient second-order J2 model for the draper semianalytic satellite theory

Semi-analytical orbit propagation methods combine the advantages of analytical and numerical methods to achieve an excellent balance between efficiency and accuracy. The increasingly congested space has led to the growing prevalence of semi-analytical methods, driven by the requirements for efficient and accurate orbit propagation in Space Situational Awareness (SSA). However, the accuracy of semi-analytical methods is only retained by considering the contribution of the J2 zonal harmonic second order terms, namely the J22 term, which has not been completely modeled in semi-analytical methods due to the complex mathematical formulations. This paper proposes a complete semi-analytical solution for the J22 contribution consistent with the Draper Semianalytic Satellite Theory (DSST), including the fully closed-form and nonsingular mean element rate equations and computationally efficient short-period terms. Firstly, for the direct application of DSST in the construction of the J22 solution, the difficulties of high computational costs induced by multiplying infinite Fourier series together are analyzed. Next, an improved construction process for the J22 solution is developed by introducing a new general form of the partial derivatives of osculating elements rates to eliminate these difficulties. Considering the complexity of the construction process, the computation details for each term in this process are then presented. Numerical experiments demonstrate that the proposed J22 solution achieves remarkable accuracy and efficiency compared to previous works.

Trap Depth Distribution Determines Afterglow Kinetics: A Local Model Applied to ZnGa2O4:Cr3.

Persistent luminescence materials have applications in diverse fields such as smart signaling, anticounterfeiting, and in vivo imaging. However, the lack of a thorough understanding of the precise mechanisms that govern persistent luminescence makes it difficult to develop ways to optimize it. Here we present an accurate model to describe the various processes that determine persistent luminescence in ZnGa2O4:Cr3+, a workhorse material in the field. A set of rate equations has been solved, and a global fit to both charge/discharge and thermoluminescence measurements has been performed. Our results establish a direct link between trap depth distribution and afterglow kinetics and shed light on the main challenges associated with persistent luminescence in ZnGa2O4:Cr3+ nanoparticles, identifying low trapping probability and optical detrapping as the main factors limiting the performance of ZnGa2O4:Cr3+, with a large margin for improvement. Our results highlight the importance of accurate modeling for the design of future afterglow materials and devices.

Rate Law for Photoelectrochemical Water Splitting over CuO

Rate Law for Photoelectrochemical Water Splitting over CuO

Unifying the ORR and OER with surface oxygen and extracting their intrinsic activities on platinum

Common half-cell measurements deliver oxygen reduction activities linked to the chosen scan rate, limiting their value for fundamental and comparative studies on platinum. Here we show a deconvolution of the intrinsic kinetics from the effect of surface oxygen on platinum. We find an electronic effect of the surface oxygen, substantiate a Tafel slope of ~120 mV/decade, obtain an exchange current density of 13 ± 4 µA/cm2, and an activity of 7 mA/cm2 at 900 mV. Eventually, we broaden the scope of this analysis to the effects of surface rearrangement, alloying, and supported Pt nanoparticles, the latter providing insight into discrepancies between half-cell and fuel cell measurements. We find through computational methods that binding energies of intermediates would be weakened by the presence of highly coordinated oxygen atoms. Finally, we obtain a phenomenological rate equation for the oxygen reduction and evolution reaction, suggesting that both reactions follow a shared mechanism.

New dimensionless equation for mass transfer at acetone evaporation under forced convection

Equations of evaporation rate were collected from literature for different liquids. These relationships directly result in the evaporation rate or the Sherwood number. Experiments were made for vaporization of acetone from a heated vessel, at different air velocities and temperatures of air and liquid surface. The effect of the different setting parameters, and the different directions of the heat flow on the evaporation rate were studied. As expected, when the air velocity and the temperature of the liquid were higher, the evaporation was faster, but when the temperature of the air was higher, the evaporation rate was lower. Based on the measurement results, a new dimensionless equation was created to determine the evaporation rate of acetone. The new equation and the correlations from the literature were compared with the results determined from the measurement data. Two of the ten correlations did not prove to be applicable to the measurement results, three correlations showed serious deviations, while five correlations gave fairly good results. Among these five correlations, the new dimensionless equation proved to be the most accurate for determining the evaporation rate of acetone in the examined range.

Kinetics of kaolinite dissolution and hydrosodalite precipitation during alkali leaching of diasporic bauxite

Alkali leaching is an effective desilication method for improving the alumina-silica mass ratio (A/S) of bauxite. The paper aims to study the kinetics of kaolinite dissolution and hydrosodalite precipitation during alkali leaching of kaolinite-rich diasporic bauxite. Alkali leaching of bauxite in NaOH solutions was studied at Na2O concentrations of 200–260 g/L, temperatures of 90–105 °C, and times of 30–150 min. The leached bauxites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) techniques. The rate equations describing kaolinite dissolution and hydrosodalite precipitation were derived by fitting the Avrami model. The results show that kaolinite with finer particle sizes was preferentially dissolved during alkali leaching, providing a material basis for the precipitation of hydrosodalite. Hydrosodalite was heterogeneously nucleated on the dissolved edges of some kaolinite and grew in both one- and two-dimensions, presenting acicular and lamellar morphology. The dissolution rate of kaolinite and the crystallization mechanism of hydrosodalite were primarily influenced by Na2O concentration and temperature. Both kaolinite dissolution and hydrosodalite precipitation were controlled by chemical reactions with activation energies of 70.152 (± 1.429) kJ/mol and 289.089 (± 2.063) kJ/mol, respectively, and the orders of reaction with respect to Na2O of 0.733 (± 0.070) and 7.165 (± 0.047), respectively. The kinetic equations describing kaolinite dissolution, hydrosodalite precipitation and even the leaching of SiO2 were eventually modeled with Na2O concentration, temperature and time as variables.

Comprehensive numerical investigations on direct ammonia-fed planar solid oxide fuel cell

This study aims at presenting comprehensive insights into the ammonia-utilization in SOFCs using a numerical model developed in 3D for a laboratory-size SOFC and also enlarged to a commercial-size to provide more realistic insights. The verification of the model using the experimental data, and the description of the Ammonia Decomposition Reaction (ACR) kinetics using a rate equation derived from a real SOFC anode make the model, computations, and analyses more accurate. Temperature appears as the most effective on the ACR rate, whereas the impacts of the cell potential and fuel feed rate are insignificant. The ACR rate and endothermic cooling peak around the fuel inlet. However, the distributions of the ACR rate, concentration of species, temperature, and current depend strongly on the active area. In the commercial-size SOFC, except the fuel inlet region, the remaining area exhibits the characteristics which are usually observed when a SOFC is fed by hydrogen.

Theoretical evidence for a pH-dependent effect of carbonate on the degradation of sulfonamide antibiotics

Carbonate (CO32−/HCO3−) have a significant impact on advanced oxidation processes (AOPs) by consuming reactive free radicals such as HO• to generate CO3•-. However, research on the mechanisms and kinetics of CO3•- remains limited. This study investigates the degradation mechanism and kinetics of sulfonamide antibiotics (SAs) by CO3•- through theoretical calculations. The calculation results revealed that the effect of CO3•- on SAs degradation is pH-dependent due to the dissociable sulfonamide group (-SO2NH-) of SAs in the common water treatment pH range (3–8). The main reaction type of CO3•- with both neutral and anionic molecules of SAs is single electron transfer reaction. Frontier molecular orbital theory (FMO) illustrated that deprotonation of the sulfonamide group of SAs decreases the charge density on the heterocyclic ring, facilitating the electrophilic addition of CO3•-. The second-order rate constants of the neutral and anionic molecules of SAs with CO3•- were calculated as 7.57 × 101∼1.84 × 108 and 1.81 × 107∼7.94 × 109 M−1 s−1, respectively, resulting in an increase in the apparent reaction rate constants with pH. Stepwise multiple linear regression was employed to predict reactivity with anionic sulfonamide antibiotics (SAs−). Two models with outstanding prediction and stability were developed with coefficients of determination R2 of 0.660 and 0.681, respectively. The degradation kinetics simulation indicated that in the UV/H2O2 process in the presence of carbonate, the degradation rate of SAs increased with pH. Furthermore, the contribution of CO3•- to SMX degradation increased while that of HO• decreased. This study highlights the contribution of carbonates to the micropollutant degradation in the UV/H2O2 process as the model, providing theoretical insights into the development of carbonate-based AOPs.