chemdose_toc: Determine TOC removal from coagulation

In tidywater: Water Quality Models for Drinking Water Treatment Processes

Determine TOC removal from coagulation

Description

This function applies the Edwards (1997) model to a water created by define_water to determine coagulated DOC. Model assumes all particulate TOC is removed; therefore TOC = DOC in output. Coagulated UVA is from U.S. EPA (2001) equation 5-80. Note that the models rely on pH of coagulation. If only raw water pH is known, utilize chemdose_ph first. For a single water use chemdose_toc; for a dataframe use chemdose_toc_chain. Use pluck_water to get values from the output water as new dataframe columns. For most arguments in the ⁠_chain⁠ helper "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

chemdose_toc(
  water,
  alum = 0,
  ferricchloride = 0,
  ferricsulfate = 0,
  coeff = "Alum"
)

chemdose_toc_chain(
  df,
  input_water = "defined_water",
  output_water = "coagulated_water",
  alum = "use_col",
  ferricchloride = "use_col",
  ferricsulfate = "use_col",
  coeff = "use_col"
)

chemdose_toc_once(
  df,
  input_water = "defined_water",
  output_water = "coagulated_water",
  alum = "use_col",
  ferricchloride = "use_col",
  ferricsulfate = "use_col",
  coeff = "use_col"
)

Arguments

water	Source water object of class "water" created by define_water. Water must include ph, doc, and uv254
alum	Amount of hydrated aluminum sulfate added in mg/L: Al2(SO4)3*14H2O + 6HCO3 -> 2Al(OH)3(am) +3SO4 + 14H2O + 6CO2
ferricchloride	Amount of ferric chloride added in mg/L: FeCl3 + 3HCO3 -> Fe(OH)3(am) + 3Cl + 3CO2
ferricsulfate	Amount of ferric sulfate added in mg/L: Fe2(SO4)3*8.8H2O + 6HCO3 -> 2Fe(OH)3(am) + 3SO4 + 8.8H2O + 6CO2
coeff	String specifying the Edwards coefficients to be used from "Alum", "Ferric", "General Alum", "General Ferric", or "Low DOC" or data frame of coefficients, which must include: k1, k2, x1, x2, x3, b
df	a data frame containing a water class column, which has already been computed using define_water_chain The df may include columns named for the chemical(s) being dosed.
input_water	name of the column of water class data to be used as the input for this function. Default is "defined_water".
output_water	name of the output column storing updated parameters with the class, Water. Default is "coagulated_water".

Value

chemdose_toc returns a single water class object with an updated DOC, TOC, and UV254 concentration.

chemdose_toc_chain returns a data frame containing a water class column with updated DOC, TOC, and UV254 concentrations.

chemdose_toc_once returns a data frame with columns for updated TOC, DOC, and UV254.

Source

Edwards (1997)

U.S. EPA (2001)

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

See Also

chemdose_ph

Examples

water <- define_water(ph = 7, temp = 25, alk = 100, toc = 3.7, doc = 3.5, uv254 = .1)
dosed_water <- chemdose_ph(water, alum = 30) %>%
  chemdose_toc(alum = 30, coeff = "Alum")

dosed_water <- chemdose_ph(water, alum = 10, h2so4 = 10) %>%
  chemdose_toc(alum = 10, coeff = data.frame(
    x1 = 280, x2 = -73.9, x3 = 4.96, k1 = -0.028, k2 = 0.23, b = 0.068
  ))


example_df <- water_df %>%
  define_water_chain() %>%
  dplyr::mutate(FerricDose = seq(1, 12, 1)) %>%
  chemdose_toc_chain(ferricchloride = FerricDose, coeff = "Ferric")

# Uncomment below to initialize parallel processing
# library(furrr)
# plan(multisession)
example_df <- water_df %>%
  define_water_chain() %>%
  dplyr::mutate(ferricchloride = seq(1, 12, 1)) %>%
  chemdose_toc_chain(coeff = "Ferric")

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



example_df <- water_df %>%
  define_water_chain() %>%
  chemdose_toc_once(input_water = "defined_water", alum = 30)

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