> My thesis involves modeling the sorption, gas phase partitioning, and biodegradation of organics in a column. I'm starting with benzene to make it simple. Instead of calling benzene C6H6, I am calling it "benzene." I have created something called "benzdp" which is the benzene daughter product, the product of a first-order biodegradation decay. The database accepts the entry of the two under solution species. However, whenever I try to connect the two in the database (Benzene = Benzdp, log_k -20 or with an equation Benzene + H2O = Benzdp + H2O), the error says the elements aren't balanced. Do you have any advice on this? To connect them in SOLUTION_SPECIES would require aqueous equilibrium. You don't really want to do this I don't think. You should leave them separate and use KINETICS to transfer from the Benzene pool to the Benzdp pool as you have done. (If you do want aqueous equilibria, you wouldn't define two separate "elements", just 1 element with two species.) > My second question involves the gas phase partitioning. I want the solution to move from cell to cell, each time encountering a new surface and gas bubble to which it will partition (sorption is working fine this way). You should be able to do this, although the gas phases do not move, which is a limitation. Just looking at your kinetics file, it seems ok except for the RATE definition. 40 rate = e^(-5.55e-5*6.3E8)#4.8day-1 "e" is interpreted as a variable that is initialized to zero, so I think your rate is always zero. "exp(-5.55e-5*6.3E8)" would be exponentiation. I think the following form is probably closer to what you want for first-order decay. 10 benz = TOT("Benzene") 20 k = 4.8/(60*60*24) # day-1 to sec-1 30 rate = benz*k # mol/kgw/sec 40 moles = rate*TIME 50 SAVE moles David David Parkhurst (dlpark@xxxxxxxx) U.S. Geological Survey Box 25046, MS 413 Denver Federal Center Denver, CO 80225 Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled
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