dissolve_pb: Simulate contributions of various lead solids to total...

In tidywater: Water Quality Models for Drinking Water Treatment Processes

Simulate contributions of various lead solids to total soluble lead

Description

This function takes a water data frame defined by define_water and outputs a dataframe of the controlling lead solid and total lead solubility. Lead solid solubility is calculated based on controlling solid. Total dissolved lead species (tot_dissolved_pb, M) are calculated based on lead complex calculations. For a single water, use dissolve_pb; to apply the model to a dataframe, use dissolve_pb_once. For most arguments, the ⁠_chain⁠ and ⁠_once⁠ helpers "use_col" default looks for a column of the same name in the dataframe. The argument can be specified directly in the function instead or an unquoted column name can be provided.

Usage

dissolve_pb(
  water,
  hydroxypyromorphite = "Schock",
  pyromorphite = "Topolska",
  laurionite = "Nasanen"
)

dissolve_pb_once(
  df,
  input_water = "defined_water",
  output_col_solid = "controlling_solid",
  output_col_result = "pb",
  hydroxypyromorphite = "Schock",
  pyromorphite = "Topolska",
  laurionite = "Nasanen",
  water_prefix = TRUE
)

Arguments

water	Source water object of class "water" created by define_water. Water must include alk and is. If po4, cl, and so4 are known, those should also be included.
hydroxypyromorphite	defaults to "Schock", the constant, K, developed by Schock et al (1996). Can also use "Zhu".
pyromorphite	defaults to "Topolska", the constant, K, developed by Topolska et al (2016). Can also use "Xie".
laurionite	defaults to "Nasanen", the constant, K, developed by Nasanen & Lindell (1976). Can also use "Lothenbach".
df	a data frame containing a water class column, which has already been computed using define_water_chain
input_water	name of the column of water class data to be used as the input. Default is "defined_water".
output_col_solid	name of the output column storing the controlling lead solid. Default is "controlling_solid".
output_col_result	name of the output column storing dissolved lead in M. Default is "pb".
water_prefix	name of the input water used for the calculation, appended to the start of output columns. Default is TRUE. Change to FALSE to remove the water prefix from output column names.

Details

The solid with lowest solubility will form the lead scale (controlling lead solid). Some lead solids have two k-constant options. The function will default to the EPA's default constants. The user may change the constants to hydroxypyromorphite = "Zhu" or pyromorphite = "Xie" or laurionite = "Lothenbach"

Make sure that total dissolved solids, conductivity, or ca, na, cl, so4 are used in define_water so that an ionic strength is calculated.

For large datasets, using fn_once or fn_chain may take many minutes to run. These types of functions use the furrr package for the option to use parallel processing and speed things up. To initialize parallel processing, use plan(multisession) or plan(multicore) (depending on your operating system) prior to your piped code with the fn_once or fn_chain functions. Note, parallel processing is best used when your code block takes more than a minute to run, shorter run times will not benefit from parallel processing.

Value

dissolve_pb returns a one row data frame containing only the controlling lead solid and modeled dissolved lead concentration.

dissolve_pb_once returns a data frame containing the controlling lead solid and modeled dissolved lead concentration as new columns.

Source

Code is from EPA's TELSS lead solubility dashboard https://github.com/USEPA/TELSS which is licensed under MIT License: Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

Wahman et al. (2021)

See references list at: https://github.com/BrownandCaldwell-Public/tidywater/wiki/References

Examples

example_pb <- define_water(
  ph = 7.5, temp = 25, alk = 93, cl = 240,
  tot_po4 = 0, so4 = 150, tds = 200
) %>%
  dissolve_pb()
example_pb <- define_water(
  ph = 7.5, temp = 25, alk = 93, cl = 240,
  tot_po4 = 0, so4 = 150, tds = 200
) %>%
  dissolve_pb(pyromorphite = "Xie")


example_df <- water_df %>%
  define_water_chain() %>%
  dissolve_pb_once(output_col_result = "dissolved_lead", pyromorphite = "Xie")


# Initialize parallel processing
library(furrr)
# plan(multisession)
example_df <- water_df %>%
  define_water_chain() %>%
  dissolve_pb_once(output_col_result = "dissolved_lead", laurionite = "Lothenbach")

# Optional: explicitly close multisession processing
# plan(sequential)

tidywater documentation built on Aug. 8, 2025, 7:15 p.m.