Cumulative relative reactivity: A concept for modeling aquifer-scale reactive transport

摘要: We simulate aquifer-scale reactive transport using an approach based on travel times and relative reactivity. The latter quantifies the intensity of chemical reaction to a reference rate with identical concentrations can be interpreted as strength electron-donor (or electron-acceptor) release by matrix, scaled release. In general, reactivity is spatially variable property reflecting geology formation. proposed approach, we track path individual water parcels through aquifer evaluate age integrated along their trajectories. By switching from spatial discretization cumulative reactivity, advective-reactive simulated solving single system ordinary differential equations for each combination in inflow. test validity two-dimensional case steady-state groundwater flow involving aerobic respiration denitrification. Here compare concentration distributions explicit virtual truth, accounting dispersive mixing, approximation show that errors introduced neglecting mixing are minor if target quantities mass fluxes crossing control plane or being collected well. further demonstrate efficiency synthetic three-dimensional study. computationally so efficient, ensemble runs assess statistical time series solutes become feasible, which not practical model. This article protected copyright. All rights reserved.