solvedose_alk: Calculate a desired chemical dose for a target alkalinity

Description

This function calculates the required amount of a chemical to dose based on a target alkalinity and existing water quality. Returns numeric value for dose in mg/L. Uses uniroot on the chemdose_ph function. For a single water, use solvedose_alk; to apply the model to a dataframe, use solvedose_alk_df. For most arguments, 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

solvedose_alk(water, target_alk, chemical)
solvedose_alk_df(
  df,
  input_water = "defined",
  output_column = "dose",
  target_alk = "use_col",
  chemical = "use_col"
)

Value

solvedose_alk returns a numeric value for the required chemical dose.

solvedose_alk_df returns a data frame containing the original data frame and columns for target alkalinity, chemical dosed, and required chemical dose.

Arguments

water: Source water of class "water" created by define_water
target_alk: The final alkalinity in mg/L as CaCO3 to be achieved after the specified chemical is added.
chemical: The chemical to be added. Current supported chemicals include: acids: "hcl", "h2so4", "h3po4", "co2", bases: "naoh", "na2co3", "nahco3", "caoh2", "mgoh2"
df: a data frame containing a water class column, which has already been computed using define_water_df. The df may include a column with names for each of the chemicals being dosed.
input_water: name of the column of water class data to be used as the input. Default is "defined_water".
output_column: name of the output column storing doses in mg/L. Default is "dose_required".

Details

solvedose_alk uses stats::uniroot() on chemdose_ph to match the required dose for the requested alkalinity target.

Examples

Run this code

dose_required <- define_water(ph = 7.9, temp = 22, alk = 100, 80, 50) %>%
  solvedose_alk(target_alk = 150, "naoh")

example_df <- water_df %>%
  define_water_df() %>%
  dplyr::mutate(finAlk = seq(100, 210, 10)) %>%
  solvedose_alk_df(chemical = "na2co3", target_alk = finAlk)