Alkalinity input-output balance

Table 21.7 Input-Output Balance for the Major Ions and Alkalinity. 

Table 15.4. Long-Term Input-Output Balance for Major Seawater Ions and Alkalinity"... 

The dynamic model presented herein builds on that reported previously (I) by incorporating the interactions between volatile acids, pH, alkalinity, gas production rate, and gas composition. The model is developed from material balances on the biological, liquid, and gas phases of a continuous-flow, complete mixing reactor. Appropriate relationships such as yield constants, an inhibition function, Henry s law, charge balances, and ionization equilibria are used to express the interactions between variables. The inputs and outputs for the reactor and the reactions considered are illustrated in Figure 2. 

The phreeqc input file is shown in Table 8.1. Note that we use sulfate for charge balance, because it is the most abundant ion. The default definition of alkalinity in phreeqc is as calcite , which is what our analysis shows, so we simply enter that number (153 mg L-1). Under the keyword REACTION, a suitable combination of moles of HCl and number of steps is found with some calculation and a certain amount of trial and error. We specify the file name of the output file to ensure we get an output file with the essential data arranged for copying to a spreadsheet. The results are shown in Figure 8.2. 

---