Defining a MSQ model

MSQ (multi solute quality) allows the modelling of several interacting chemicals in the water system.

The core of a MSQ model is defined on the five MSQ tabs of the Solute Data Object dialog.

To define a MSQ model:

1. On the MSQ Solutes tab, define several solutes.

   For each solute, specify whether it is Bulk (Dissolved) or Wall (Adsorbed).

   Also define the default global initial concentrations.

   Note: A defined solute is either “wall” or “bulk”. If a chemical can exist both as dissolved and adsorbed, then define two solutes and provide an equation for conversion between the two states.

2. If required, use the MSQ Constants tab to add numerical constants to equations.
3. If required, use the MSQ Variables tab to combine constants and operators as reusable “phrases” in equations.

   For example, “KF = 1.5E-5*RE^0.88/DIAM” combines the Reynolds number and pipe diameter into [????] as part of a phrase.

4. Use the MSQ Reservoir Equations tab to define the conversion between substances within the body of reservoirs.
5. Use the MSQ Pipe Equations tab to define the conversion between substances within the body and wall of pipes and other link types.

   As an example, the following equations are a simplified subset of what might go on in a pipe. This looks at the conversion of dissolved Arsenite (As3) to dissolved Arsenate (As5), mediated by Chloramine:

   DDT( As3 ) = -KA*As3*NH2CL

   DDT( As5 ) = KA*As3*NH2CL

   Note: A full model would include more processes within a pipe, such as loss of Chloramine and adsorption to the wall.