chemdose_chlordecay_chain function

Apply chemdose_chlordecay within a data frame and output a column of water class to be chained to other tidywater functions

This function allows chemdose_chlordecay to be added to a piped data frame. Its output is a water class, and can therefore be used with "downstream" tidywater functions. free_chlorine or combined_chlorine slots will be updated depending on chlorine type.

chemdose_chlordecay_chain(
  df,
  input_water = "defined_water",
  output_water = "disinfected_water",
  cl2_dose = 0,
  time = 0,
  treatment = "raw",
  cl_type = "chlorine"
)

Arguments

• df: a data frame containing a water class column, which has already been computed using define_water_chain. The df may include a column named for the applied chlorine dose (cl2_dose), and a column for time in hours.
• 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 "disinfected_water".
• cl2_dose: Applied chlorine or chloramine dose (mg/L as cl2). Model results are valid for doses between 0.995 and 41.7 mg/L for raw water, and for doses between 1.11 and 24.7 mg/L for coagulated water.
• time: Reaction time (hours). Chlorine decay model results are valid for reaction times between 0.25 and 120 hours. Chloramine decay model does not have specified boundary conditions.
• treatment: Type of treatment applied to the water. Options include "raw" for no treatment (default), "coag" for water that has been coagulated or softened.
• cl_type: Type of chlorination applied, either "chlorine" (default) or "chloramine".

Returns

A data frame containing a water class column with updated chlorine residuals.

Details

The data input comes from a water class column, as initialized in define_water_chain.

If the input data frame has a chlorine dose column (cl2_dose) or time column (time), the function will use those columns. Note: The function can only take cl2_dose and time inputs as EITHER a column or as function arguments, not both.

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.

Examples

library(purrr)
library(furrr)
library(tidyr)
library(dplyr)

example_df <- water_df %>%
  mutate(br = 50) %>%
  define_water_chain() %>%
  balance_ions_chain() %>%
  chemdose_chlordecay_chain(input_water = "balanced_water", cl2_dose = 4, time = 8)

example_df <- water_df %>%
  mutate(br = 50) %>%
  define_water_chain() %>%
  balance_ions_chain() %>%
  mutate(
    cl2_dose = seq(2, 24, 2),
    time = 30
  ) %>%
  chemdose_chlordecay_chain(input_water = "balanced_water")

example_df <- water_df %>%
  mutate(br = 80) %>%
  define_water_chain() %>%
  balance_ions_chain() %>%
  mutate(time = 8) %>%
  chemdose_chlordecay_chain(
    input_water = "balanced_water", cl2_dose = 6, treatment = "coag",
    cl_type = "chloramine"
  )

# Initialize parallel processing
plan(multisession, workers = 2) # Remove the workers argument to use all available compute
example_df <- water_df %>%
  mutate(br = 50) %>%
  define_water_chain() %>%
  balance_ions_chain() %>%
  chemdose_chlordecay_chain(input_water = "balanced_water", cl2_dose = 4, time = 8)

# Optional: explicitly close multisession processing
plan(sequential)

See Also

chemdose_chlordecay