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_df.
Use pluck_cols = TRUE to get values from the output water as new dataframe columns.
For most arguments in the _df 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",
caoh2 = 0
)
chemdose_toc_df(
df,
input_water = "defined",
output_water = "coagulated",
pluck_cols = FALSE,
water_prefix = TRUE,
alum = "use_col",
ferricchloride = "use_col",
ferricsulfate = "use_col",
caoh2 = "use_col",
coeff = "use_col"
)Source
Edwards (1997)
U.S. EPA (2001)
See reference list at: https://github.com/BrownandCaldwell-Public/tidywater/wiki/References
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
- caoh2
Option to add caoh2 in mg/L to soften the water. Will predict DOC, TOC, UV254 using a modified equation (see reference list). Defaults to zero.
- df
a data frame containing a water class column, which has already been computed using define_water_df. The df may include a column named for the coagulant being dosed, and a column named for the set of coefficients to use.
- input_water
name of the column of water class data to be used as the input for this function. Default is "defined".
- output_water
name of the output column storing updated water class object. Default is "coagulated".
- pluck_cols
Extract water slots modified by the function (doc, toc, uv254) into new numeric columns for easy access. Default to FALSE.
- water_prefix
Append the output_water name to the start of the plucked columns. Default is TRUE.
Value
chemdose_toc returns a single water class object with an updated DOC, TOC, and UV254 concentration.
chemdose_toc_df returns a data frame containing a water class column with updated DOC, TOC, and UV254
concentrations. Optionally, it also adds columns for each of those slots individually.
Examples
water <- define_water(ph = 7, temp = 25, alk = 100, toc = 3.7, doc = 3.5, uv254 = .1)
#> Warning: Major ions missing and neither TDS or conductivity entered. Ideal conditions will be assumed. Ionic strength will be set to NA and activity coefficients in future calculations will be set to 1.
dosed_water <- chemdose_ph(water, alum = 30) %>%
chemdose_toc(alum = 30, coeff = "Alum")
#> Warning: Sulfate-containing chemical dosed, but so4 water slot is NA. Slot not updated because background so4 unknown.
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
))
#> Warning: Sulfate-containing chemical dosed, but so4 water slot is NA. Slot not updated because background so4 unknown.
# \donttest{
example_df <- water_df %>%
define_water_df() %>%
dplyr::mutate(FerricDose = seq(1, 12, 1)) %>%
chemdose_toc_df(ferricchloride = FerricDose, coeff = "Ferric")
example_df <- water_df %>%
define_water_df() %>%
dplyr::mutate(ferricchloride = seq(1, 12, 1)) %>%
chemdose_toc_df(coeff = "Ferric", pluck_cols = TRUE)
# }