Theoretical equilibrium lead(II) solubility revisited: Open source code and practical relationships.

A theoretical equilibrium lead(II) (Pb(II)) solubility model coded in Fortran (LEADSOL) was updated and implemented in open source R code, verified against LEADSOL output, and used to simulate theoretical equilibrium total soluble Pb(II) (TOTSOLPb) concentrations under a variety of practical scenarios. The developed R code file (app.R) is publicly available for download at GitHub (https://github.com/USEPA/TELSS) along with instructions to run the R code locally, allowing the user to explore Pb(II) solubility by selecting desired simulation conditions (e.g., water quality, equilibrium constants, and Pb(II) solids to consider). In addition, the R code serves as a reproducible baseline for alternative model development and future model improvements, allowing users to update, modify, and share the R code to meet their needs. Using the R code, several solubility diagrams were generated to highlight practical relationships related to TOTSOLPb concentrations, including the impact of pH and dissolved inorganic carbon, orthophosphate, sulfate, and chloride concentrations.