Heat transport (U,S) Can affect reaction Thermal conductivity; Tier 2 parameters heat capacity Chemical processes Radioactive (U,S) Single species first-order Decay rates (first order) Tier 2 decay; multi-species with chained decay reactions Colloidal transport/sorption Flocculation and Concentration of Tier 2 on colloidal particles (U,S) precipitation; sorption of suspended particles; contaminants on local fraction of the colloidal mineral immobile matrix that is surfaces covered by deposited particles or mass of retained particles; particle radius; specific surface area Redox reactions (U,S) Reactions involving the Chemical speciation; Tier 2 transfer of electrons dissolved oxygen; charge between two chemical of the aqueous phase species Sorption/desorption (U,S) Adsorption is the Adsorption on to the solid Tier 2 accumulation of phase described by linear chemicals on solid or non-linear equilibrium phases; desorption is isotherm coefficients the reverse of adsorption involving the release of chemicals from solid phases Ion exchange (U,S) Reversible exchange of Chemical speciation, Tier 2 ions of the same polarity including exchangeable between solution and species; mineralogy of solid matrix the porous selectivity coefficients Volatilisation (U,S) Conversion of volatile Chemical partition Tier 2 chemical constituents in constants vadose zone and groundwater to vapour Precipitation/dissolution Precipitation involves the Chemical speciation; Tier 2 (U,S) contaminant becoming solubility product insoluble; dissolution constants for different involves fluid minerals; temperature, interactions with the partial pressure of CO2 aquifer resulting in the dissociation of ions Complexation (U,S) Metal atom or ions Stability constant Tier 2 associate with a group of neutral molecules or anions
Heat transport (U,S) Can affect reaction parameters Thermal conductivity; heat capacity Tier 2 Chemical processes Radioactive (U,S) Single species first-order decay; multi-species with chained decay reactions Decay rates (first order) Tier 2 Colloidal transport/sorption on colloidal particles (U,S) Flocculation and precipitation; sorption of contaminants on colloidal mineral surfaces Concentration of suspended particles; local fraction of the immobile matrix that is covered by deposited particles or mass of retained particles; particle radius; specific surface area Tier 2 Redox reactions (U,S) Reactions involving the transfer of electrons between two chemical species Chemical speciation; dissolved oxygen; charge of the aqueous phase Tier 2 Sorption/desorption (U,S) Adsorption is the accumulation of chemicals on solid phases; desorption is the reverse of adsorption involving the release of chemicals from solid phases Adsorption on to the solid phase described by linear or non-linear equilibrium isotherm coefficients Tier 2 Ion exchange (U,S) Reversible exchange of ions of the same polarity between solution and solid matrix Chemical speciation, including exchangeable species; mineralogy of the porous selectivity coefficients Tier 2 Volatilisation (U,S) Conversion of volatile chemical constituents in vadose zone and groundwater to vapour Chemical partition constants Tier 2 Precipitation/dissolution (U,S) Precipitation involves the contaminant becoming insoluble; dissolution involves fluid interactions with the aquifer resulting in the dissociation of ions Chemical speciation; solubility product constants for different minerals; temperature, partial pressure of CO2 Tier 2 Complexation (U,S) Metal atom or ions associate with a group of neutral molecules or anions Stability constant Tier 2