This function takes a water defined by define_water() and the first order decay curve parameters
from an ozone dose and outputs a dataframe of actual CT, and log removal for giardia, virus, and crypto.
For a single water, use solvect_o3; to apply the model to a dataframe, use solvect_o3_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
solvect_o3(water, time, dose, kd, baffle)
solvect_o3_df(
df,
input_water = "defined",
time = "use_col",
dose = "use_col",
kd = "use_col",
baffle = "use_col",
water_prefix = TRUE
)Source
USEPA (2020) Equation 4-4 through 4-7 https://www.epa.gov/system/files/documents/2022-02/disprof_bench_3rules_final_508.pdf
See references list at: https://github.com/BrownandCaldwell-Public/tidywater/wiki/References
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.
- dose
Ozone dose in mg/L. This value can also be the y intercept of the decay curve (often slightly lower than ozone dose.)
- kd
First order decay constant. This parameter is optional. If not specified, the default ozone decay equations will be used.
- baffle
Baffle factor - unitless value between 0 and 1.
- 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.
Value
solvect_o3 returns a data frame containing actual CT (mg/L*min), giardia log removal, virus log removal, and crypto log removal.
solvect_o3_df returns a data frame containing the original data frame and columns for required CT, actual CT, and giardia log removal.
Details
First order decay curve for ozone has the form: residual = dose * exp(kd*time). kd should be a negative number.
Actual CT is an integration of the first order curve. The first 30 seconds are removed from the integral to account for
instantaneous demand.
When kd is not specified, a default decay curve is used from the Water Treatment Plant Model (2002). This model does
not perform well for ozone decay, so specifying the decay curve is recommended.
Examples
# Use kd from experimental data (recommended):
define_water(ph = 7.5, temp = 25) %>%
solvect_o3(time = 10, dose = 2, kd = -0.5, baffle = 0.9)
#> Warning: Missing value for alkalinity. Carbonate balance will not be calculated.
#> 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.
#> ct_actual glog_removal vlog_removal clog_removal
#> 1 2.779426 17.22941 34.85294 1.131231
# Use modeled decay curve:
define_water(ph = 7.5, alk = 100, doc = 2, uv254 = .02, br = 50) %>%
solvect_o3(time = 10, dose = 2, baffle = 0.5)
#> Warning: Missing value for TOC. DOC assumed to be 95% of TOC.
#> 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.
#> ct_actual glog_removal vlog_removal clog_removal
#> 1 4.624554 28.66719 57.99013 1.882201
# \donttest{
ct_calc <- water_df %>%
dplyr::mutate(br = 50) %>%
define_water_df() %>%
dplyr::mutate(
dose = 2,
O3time = 10,
) %>%
solvect_o3_df(time = O3time, baffle = .7)
# }