McKay, Donald. "Front matter" Multimedia Environmental Models ...

Table 8.3 D Values in the QWASI Model and Their Multiplying Fugacity
Definition of D Multiplying
Process D Value
Value
Fugacity
Sediment burial DB GBZS fS Sediment transformation DS VSZSkS fS Sediment resuspension DR GRZS fS Sediment to water diffusion DT kTASZW fS Water to sediment diffusion DT kTASZW fW Sediment deposition DD GDZP fW Water transformation DW VWZWkW fW Volatilization DV kVAWZW fW Absorption DV kVAWZW fA Water outflow DJ GJZW fW Water particle outflow DY GYZP fW Rain dissolution DM GMZW fA Wet particle deposition DC GCZQ fA Dry particle deposition DQ GQZQ fA Water inflow DI GIZW fI Water particle inflow DX GXZP fI Direct emissions
Nomenclature and Explanation
— EW The rate (mol/h) is the product of the D Value and the multiplying fugacity, e.g., DBfS. G values are flows (m3 /h) of a phase, e.g., GB is m3 /h of sediment that is buried.
fW, fS, fA, and fI are the fugacities of water, sediment, air and water inflow.
Z values are fugacity capacities (mol/m3 Pa), the subscript being S sediment, W water, A
air, Q aerosol, P water particles.
The advective flows are subscripted I water inflow, X water particle inflow, J water outflow,
and Y water particle outflow.
kS and kW are sediment and water transformation rate constants (h –1 ).
kT is a sediment–water mass transfer coefficient and kV an overall (water–side) air–water
mass transfer coefficient (m/h).
AW and AS are air–water and water–sediment areas (m2 ).
VW and VS are water and sediment volumes (m3 ).
retained in the sediment, with the remaining fraction (D R + D T)/(D R + D T + D S + D B)
being returned to the water. The three terms in the numerator of the f W equation give
the inputs from emissions, inflow, and transfer from air.
When the equations are solved, the concentrations, amounts, and fluxes can be
calculated. An illustration of such an output is given in Figure 8.6 for PCBs in Lake
Ontario (Mackay, 1989). Such mass balance diagrams clearly show which processes
are most important for the chemical of interest.
Windows- and DOS-based BASIC programs are provided that process the various
Z values, volumes, areas, flows, D values, and the chemical input parameters
to give the steady-state solution. The conditions simulated in the BASIC program
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