PHREEQC Input File Generator for Mine Drainage Systems

Mine drainage systems pose significant environmental challenges due to the release of metals, sulfate, and acidity from sulfide oxidation in waste rock and tailings. Accurate prediction of long-term water quality requires robust geochemical modeling—PHREEQC excels in speciation, saturation index calculation, kinetic mineral dissolution/precipitation, and one-dimensional reactive transport simulations. However, constructing syntactically correct PHREEQC input files manually is time-intensive and error-prone, especially when handling multiple sampling points, time-series data, or scenario-based sensitivity analyses. The Excel-based generator addresses this by providing structured worksheets for entering analytical data (e.g., pH, major ions, trace metals), solid-phase composition (e.g., pyrite, gypsum, ferrihydrite), thermodynamic database selection (e.g., minteq.v4.dat, phreeqc.dat), and user-defined reactions (e.g., O2 diffusion, organic matter oxidation). It applies built-in validation checks (e.g., charge balance tolerance, unit consistency, redox pairing) and auto-generates commented, modular PHREEQC scripts with embedded documentation. Advanced versions support batch generation for spatial grids or temporal scenarios, enabling rapid comparative analysis of treatment options (e.g., limestone dosing vs. anoxic limestone drains) or climate-driven changes in recharge chemistry.