To illustrate the use of treatment flux links, consider a simple case involving removal of a two species from one Cell (a tank) before it flows to a second Cell (a second tank). This particular example file, Cell6_Treatment.gsm, can be found in the Contaminant Transport Examples folder in your GoldSim directory (accessed by selecting File | Open Example... from the main menu).
Suppose that the tank contains 10 m3 of water. Water cycles through the tank at a rate of 1 m3/day (flowing to an equal sized tank). The incoming water contains Fe at a concentration of 1 mg/l and 1 mg/l of Zn. A treatment process in the tank removes 99% of the Fe and 92% of the Zn.
To simulate this system, you would do the following:
1. Define two Species (Fe and Zn).
2. Create a Cell called Treatment_Tank containing 10 m3 of Water;
3. Create a Cell called Sink_Downstream containing 1m3 of Water (the amount of Water is not important, as this Cell is simply acting as a sink for the water leaving the Treatment_Tank);
4. Create a Cell called Sink_Mass containing 1 m3 of Water (the amount of Water is not important, as this Cell is simply acting as a sink for the treated mass);
5. Create an Input Rate for Treatment_Tank equal to 1 mg/l * 1 m3/day for each species (equivalent to mass entering at a rate of 1 g/day);
6. Create an advective mass flux link between Treatment_Tank and Sink_Downstream with a flow rate of 1 m3/day.
7. Create a treatment flux link between the Treatment_Tank and Sink_Mass with the appropriate removal fractions; and
8. Specify the simulation settings (i.e., duration and timesteps), and run the model.
The output of this simulation, in the form of time histories of mass removal rate (the mass rate from Treatment_Tank to Sink_Mass) is shown below:
Note that 0.99 g/day of Fe is removed, and 0.92 g/day of Zn is removed. Recall that the amount of mass entering the Treatment_Tank is 1 g/day for each species.