AquaEnv (version 1.0-1)

titration: titration

Description

PUBLIC function: creates an object of class aquaenv which contains a titration simulation

Usage

titration(aquaenv, mass_sample, mass_titrant, conc_titrant,
          S_titrant=NULL, steps, type="HCl", seawater_titrant=FALSE,
          k_w=NULL, k_co2=NULL, k_hco3=NULL, k_boh3=NULL, k_hso4=NULL,
          k_hf=NULL, k1k2="roy", khf="dickson")

Arguments

aquaenv

an object of type aquaenv: minimal definition, contains all information about the system: T, S, d, total concentrations of nutrients etc (Note that it is possible to give values for SumBOH4, SumHSO4, and SumHF in the sample other than the ones calculated

mass_sample

the mass of the sample solution in kg

mass_titrant

the total mass of the added titrant solution in kg

conc_titrant

the concentration of the titrant solution in mol/kg-soln

S_titrant

the salinity of the titrant solution, if not supplied it is assumed that the titrant solution has the same salinity as the sample solution

steps

the amount of steps the mass of titrant is added in

type

the type of titrant: either "HCl" or "NaOH", default: "HCl"

seawater_titrant

is the titrant based on natural seawater? (does it contain SumBOH4, SumHSO4, and SumHF in the same proportions as seawater, i.e., correlated to S?); Note that you can only assume a seawater based titrant (i.e. SumBOH4, SumHSO4, and SumHF ~ S)

k_w

a fixed K_W can be specified

k_co2

a fixed K_CO2 can be specified; used for TA fitting: give a K_CO2 and NOT calculate it from T and S: i.e. K_CO2 can be fitted in the routine as well

k_hco3

a fixed K_HCO3 can be specified

k_boh3

a fixed K_BOH3 can be specified

k_hso4

a fixed K_HSO4 can be specified

k_hf

a fixed K_HF can be specified

k1k2

either "roy" (default, Roy1993a) or "lueker" (Lueker2000) for K_CO2 and K_HCO3.

khf

either "dickson" (default, Dickson1979a) or "perez" (Perez1987a) for K_HF

Value

• object of class aquaenv which contains a titration simulation

Examples

####################
# Titration with HCl
####################
S <- 35
t <- 15

SumCO2 <- 0.003500
SumNH4 <- 0.000020

mass_sample  <- 0.01 # the mass of the sample solution in kg
mass_titrant <- 0.02 # the total mass of the added titrant solution in
                     # kg
conc_titrant <- 0.01 # the concentration of the titrant solution in
                     # mol/kg-soln
S_titrant    <- 0.5  # the salinity of the titrant solution (the
                     # salinity of a solution with a ionic strength of
                     # 0.01 according to: I = (19.924 S) / (1000 - 1.005S)
steps        <- 50   # the amount of steps the mass of titrant is added
                     # in
type         <- "HCl"

pHstart <- 11.3


ae <- titration(aquaenv(S=S, t=t, SumCO2=SumCO2, SumNH4=SumNH4,
                pH=pHstart), mass_sample, mass_titrant, conc_titrant,
                S_titrant, steps, type)


# plotting everything
plot(ae, xval=ae$delta_mass_titrant, xlab="HCl solution added [kg]",
mfrow=c(10,10))


# plotting selectively
size  <- c(12,8) #inches
mfrow <- c(4,4)
what  <- c("TA", "pH", "CO2", "HCO3", "CO3", "BOH3", "BOH4", "OH",
           "NH4", "NH3", "H2SO4", "HSO4", "SO4", "HF", "F", "pCO2")


plot(ae, xval=ae$delta_mass_titrant, xlab="HCl solution added [kg]",
     what=what, size=size, mfrow=mfrow)

plot(ae, xval=ae$pH, xlab="free scale pH", what=what, size=size,
     mfrow=mfrow)


# different x values
plot(ae, xval=ae$delta_conc_titrant, xlab="[HCl] offset added
     [mol/kg-soln]", what=what, size=size, mfrow=mfrow)

plot(ae, xval=ae$delta_moles_titrant, xlab="HCl added [mol]", what=what,
     size=size, mfrow=mfrow)


# bjerrum plots
par(mfrow=c(1,1))
plot(ae, bjerrum=TRUE)

what  <- c("CO2", "HCO3", "CO3")
plot(ae, what=what, bjerrum=TRUE)
plot(ae, what=what, bjerrum=TRUE, lwd=4, palette=c("cyan", "magenta",
     "yellow"), bg="gray", legendinset=0.1, legendposition="topleft")



what  <- c("CO2", "HCO3", "CO3", "BOH3", "BOH4", "OH", "NH4", "NH3",
           "H2SO4", "HSO4", "SO4", "HF", "F")

plot(ae, what=what, bjerrum=TRUE, log=TRUE)
plot(ae, what=what, bjerrum=TRUE, log=TRUE, ylim=c(-6,-1),
     legendinset=0, lwd=3, palette=c(1,3,4,5,6,colors()[seq(100,250,6)]))