Calculates the required amount of a chemical to dose based on a target pH and existing water quality.
The function takes an object of class "water", and user-specified chemical and target pH
and returns a numeric value for the required dose in mg/L.
For a single water, use solvedose_ph; to apply the model to a dataframe, use solvedose_ph_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_ph(water, target_ph, chemical)
solvedose_ph_df(
df,
input_water = "defined",
output_column = "dose",
target_ph = "use_col",
chemical = "use_col"
)Arguments
- water
Source water of class "water" created by define_water
- target_ph
The final pH 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".
- output_column
name of the output column storing doses in mg/L. Default is "dose".
Value
solvedose_ph returns a numeric value for the required chemical dose.
solvedose_ph_df returns a data frame containing the original data frame and columns for target pH, chemical dosed, and required chemical dose.
Details
solvedose_ph uses stats::uniroot() on chemdose_ph to match the required dose for the requested pH target.
Examples
water <- define_water(ph = 7, temp = 25, alk = 10)
#> 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.
# Calculate required dose of lime to reach pH 8
solvedose_ph(water, target_ph = 8, chemical = "caoh2")
#> [1] 1.5
example_df <- water_df %>%
define_water_df() %>%
solvedose_ph_df(input_water = "defined", target_ph = 8.8, chemical = "naoh")