Some parameters in toxics module

I’d like to know what “volatilization rate” mean and how to calculate the “volatilization rate” .
What are the differences between “WC Partition Coeff” and “Bed Partition Coeff” ?
Thanks a lot.
Attached files

Volatilization is a process by which dissolved phase organic chemicals can be transferred out of the water column at the air/water interface, with the rate of transfer being generally lower for more hydrophobic compounds with higher molecular weights such as PCBs and PAHs.

The partition coefficient represents the ratio of particulate-bound chemical concentration to the concentration of the chemical in the freely dissolved phased at equilibrium. Partitioning affects concentrations of chemicals that adsorb to depositing sediment, concentrations within sediment porewater, and exposure/risk to biota.

Partition coefficients of a chemical is different in water column and sediment bed so you will have to specify the parition coefficient for both water column and sediments. Field studies have to be performed to find the particulate concentration and dissolved phase concentrations. Partition coefficients for some chemicals can be found in the following papers:
Hawker and Connell (1988), de Brujin (1989), Di Toro(1985) etc.

Janesh Devkota