CHROMAT{trademark} Version 1.1--Soil Chromium Attenuation Evaluation Model. User`s manual and technical reference

This document is the user`s manual and technical reference for the Soil Chromium Attenuation Model (CHROMAT{trademark}), a computer code designed to calculate both the dissolved Cr concentration and the amount of Cr attenuated in soils as a result of the geochemical reactions that occur as Cr-containing leachates migrate through porous soils. The dissolved Cr concentration and the amount of Cr attenuated are calculated using thermodynamic (mechanistic) data for aqueous complexation reactions, adsorption/ desorption reactions, and precipitation/dissolution reactions involving both CR(III) and Cr(VI) species. Use of this mechanistic approach means that CHROMAT{trademark} requires a minimum amount of site-specific data on leachate and soil characteristics. CHROMAT{trademark} is distributed in executable form for IBM and IBM-compatible personal computers through a license from the Electric Power Research Institute (EPRI). The user interacts with CHROMAT{trademark} using menu-driven screen displays. Interactive on-line help options are available. Output from the code can be obtained in tabular or graphic form. This manual describes the development of CHROMAT{trademark}, including experimental data development in support of the model and model validation studies. The thermodynamic data and computational algorithm are also described. Example problems and results are included.