tidywater (version 0.10.0)

gac_toc: Calculate TOC Concentration in GAC system

Description

Calculates TOC concentration after passing through GAC treatment according to the model developed in "Modeling TOC Breakthrough in Granular Activated Carbon Adsorbers" by Zachman and Summers (2010), or the logistics curve approach in EPA WTP Model v. 2.0 Manual (2001). For a single water use gac_toc; for a dataframe use gac_toc_df. Use pluck_water 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.

Water must contain DOC or TOC value.

Usage

gac_toc(
  water,
  ebct = 10,
  model = "Zachman",
  media_size = "12x40",
  bed_vol,
  pretreat = "coag"
)
gac_toc_df(
  df,
  input_water = "defined",
  output_water = "gaced",
  model = "use_col",
  pluck_cols = FALSE,
  water_prefix = TRUE,
  media_size = "use_col",
  ebct = "use_col",
  bed_vol = "use_col",
  pretreat = "use_col"
)

Value

gac_toc returns a water class object with updated DOC, TOC, and UV254 slots.

gac_toc_df returns a data frame containing a water class column with updated DOC, TOC, and UV254 slots

Arguments

water

Source water object of class "water" created by define_water

ebct

Empty bed contact time (minutes). Model results are valid for 10 or 20 minutes. Defaults to 10 minutes.

model

Specifies which GAC TOC removal model to apply. Options are Zachman and WTP. Defaults to Zachman.

media_size

Size of GAC filter mesh. Model includes 12x40 and 8x30 mesh sizes. Defaults to 12x40.

bed_vol

Bed volume of GAC filter to predict effluent TOC for.

pretreat

Specifies the level of pretreatment prior to GAC treatment. Defaults to "coag". Other option is coagulant, ozonation, and biotreatment, called "o3biof".

df

a data frame containing a water class column, which has already been computed using define_water_df. The df may include columns named for the media_size, ebct, and bed volume.

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 parameters with the class, water. Default is "gaced".

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.

Details

GAC model for TOC removal

The function will calculate TOC concentration by GAC adsorption in drinking water treatment. UV254 concentrations are predicted based on a linear relationship with DOC from WTP Model Equation 5-93 and 5-94.

Examples

water <- define_water(ph = 8, toc = 2.5, uv254 = .05, doc = 1.5) %>%
  gac_toc(media_size = "8x30", ebct = 20, model = "Zachman", bed_vol = 15000)

# \donttest{
example_df <- water_df %>%
  define_water_df() %>%
  dplyr::mutate(
    model = "WTP",
    media_size = "8x30",
    ebct = 10,
    bed_vol = rep(c(12000, 15000, 18000), 4)
  ) %>%
  gac_toc_df()

example_df <- water_df %>%
  define_water_df("raw") %>%
  dplyr::mutate(
    model = "WTP",
    bed_vol = 15000
  ) %>%
  gac_toc_df(input_water = "raw")
# }