tidywater (version 0.10.0)

solvect_chlorine: Determine disinfection credit from chlorine.

Description

This function takes a water defined by define_water and other disinfection parameters and outputs a data frame of the required CT (ct_required), actual CT (ct_actual), and giardia log removal (glog_removal). For a single water, use solvect_chlorine; to apply the model to a dataframe, use solvect_chlorine_df. For most arguments, the _df helpers "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

solvect_chlorine(water, time, residual, baffle, free_cl_slot = "residual_only")
solvect_chlorine_df(
  df,
  input_water = "defined",
  time = "use_col",
  residual = "use_col",
  baffle = "use_col",
  free_cl_slot = "residual_only",
  water_prefix = TRUE
)

Value

solvect_chlorine returns a data frame containing required CT (mg/Lmin), actual CT (mg/Lmin), giardia log removal, and virus log removal.

solvect_chlorine_df returns a data frame containing the original data frame and columns for required CT, actual CT, and giardia log removal.

Arguments

water

Source water object of class "water" created by define_water. Water must include ph and temp

time

Retention time of disinfection segment in minutes.

residual

Minimum chlorine residual in disinfection segment in mg/L as Cl2.

baffle

Baffle factor - unitless value between 0 and 1.

free_cl_slot

Defaults to "residual_only", which uses the residual argument. If "slot_only", the model will use the free_chlorine slot in the input water. "sum_with_residual", will use the sum of the residual argument and the free_chlorine slot.

df

a data frame containing a water class column, which has already been computed using define_water_df

input_water

name of the column of Water class data to be used as the input for this function. Default is "defined_water".

water_prefix

name of the input water used for the calculation will be appended to the start of output columns. Default is TRUE.

Details

CT actual is a function of time, chlorine residual, and baffle factor, whereas CT required is a function of pH, temperature, chlorine residual, and the standard 0.5 log removal of giardia requirement. CT required is an empirical regression equation developed by Smith et al. (1995) to provide conservative estimates for CT tables in USEPA Disinfection Profiling Guidance. Log removal is a rearrangement of the CT equations.

Examples

example_ct <- define_water(ph = 7.5, temp = 25) %>%
  solvect_chlorine(time = 30, residual = 1, baffle = 0.7)
ct_calc <- water_df %>%
  define_water_df() %>%
  solvect_chlorine_df(residual = 2, time = 10, baffle = .5)

chlor_resid <- water_df %>%
  dplyr::mutate(br = 50) %>%
  define_water_df() %>%
  dplyr::mutate(
    residual = seq(1, 12, 1),
    time = seq(2, 24, 2),
    baffle = 0.7
  ) %>%
  solvect_chlorine_df()