Aqueous-Phase-Chemistry

ModelingToolkit implementation of the characteristic timescale for aqueous-phase chemical reaction within a cloud droplet or wetted aerosol particle, from Seinfeld & Pandis (2006), Atmospheric Chemistry and Physics, 2nd ed., Chapter 12, Eqs. 12.76-12.78. The component reports two diagnostics for a first-order aqueous reaction: the aqueous-phase reaction timescale τ_ra = 1/k_rxn (Eq. 12.76), the e-folding time of a dissolved species consumed by a first-order reaction of rate constant k_rxn; and the gas-phase reference reaction timescale τ_rg = τ_ra/(H*·R·T) (Eq. 12.78), the same timescale referenced to the gas phase through the dimensionless effective Henry's law solubility H*·R·T. Migrated from Aerosol.jl ReactionTimescale. Purely algebraic: no differential states, two observed outputs and an empty equations array.

ModelingToolkit implementation of the aqueous-phase S(IV)→S(VI) oxidation rate catalyzed by dissolved Fe(III), from Seinfeld & Pandis (2006), Atmospheric Chemistry and Physics, 2nd ed., Chapter 7, Eq. 7.92. The component reports a single diagnostic, the Fe(III)-catalyzed oxidation rate R_Fe = k·[Fe(III)]·[S(IV)]/[H+], for the low-pH (pH 0-3.6) regime: the rate rises in proportion to the dissolved-iron catalyst and the total S(IV) substrate, and falls inversely with the hydrogen-ion concentration. Migrated from Aerosol.jl SulfateFormationFe. Purely algebraic: no differential states, one observed output and an empty equations array.

ModelingToolkit implementation of the S(IV) → S(VI) aqueous-phase oxidation rate catalysed by O2 with Fe(III)/Mn(II) synergism, from Seinfeld & Pandis (2006), Atmospheric Chemistry and Physics, 2nd ed., Chapter 7, Section 7.5.5, Eq. 7.102. The component reports the three additive contributions to the catalysed oxidation rate of dissolved S(IV) — a Mn(II)-only term (k_Mn·[Mn(II)]·[S(IV)]), an Fe(III)-only term (k_Fe·[Fe(III)]·[S(IV)]), and a synergistic term (k_FeMn·[Mn(II)]·[Fe(III)]·[S(IV)]) that is greatly enhanced when both transition metals are present — together with their sum R_FeMn. Migrated from Aerosol.jl SulfateFormationFeMn. Purely algebraic: no differential states; the four rate outputs are algebraic states defined by four equations.