Contaminant Transport at a Waste Residue Deposit: 2. Geochemical Transport Modeling

Abstract

Contaminant transport in an aquifer at an incinerator waste residue deposit in Denmark is simulated. A two‐dimensional, geochemical transport code is developed for this purpose and tested by comparison to results from another code. The code is applied to a column experiment and to the field site. The ongoing geochemical processes and any unknown geochemical parameters are obtained through simulation of the column experiment that used soil and leachate from the field site. The application of the code to the field site, which has been monitored for more than 15 years, use this geochemical information along with the flow and nonreactive transport parameters obtained by the inverse modeling procedure described in the first paper [Sonnenborg et al., this issue] of this two‐paper series. The simulation results of the site model are compared with several measured component breakthroughs at monitoring wells. Contamination was first controlled by transport, and later by transport and ion exchange. In both the column and field site simulations the code is used to identify the controlling transport processes, physical or geochemical (ion exchange and mineral precipitation), and to estimate the involved parameters (primarily ion exchange selectivity coefficients).