There are two general ways to model this with WaterGEMS. The simpler way is to model DBP formation as a constituent that grows to reach an equilibrium concentration. You would start with a calibrated EPS model and then define a bulk and wall reaction rate and equilibrium concentration. You can try to get a handle on the bulk and equilibrium values with some bottle tests in the lab. If you want to have confidence in the model, you will eventually need to do some field calibration work until you can reasonably match the field measurements. You can adjust the reaction rate for temperature using K2 = K1 Theta^(T2-T1) where Theta is usually on the order of 1.04 and K1 is the rate constant at temperature T1. A more thorough but difficult approach is to use our multi-species extension which enables you to more accurately model the reactions between chlorine, DBP's and precursors. You need to set up rate reaction equations for the interactions between the three (or more constituents) and determine the reaction constants for your water. This is only available for SELECTseries 5.
↧