Modify influent fractionation for a given influent characterization

Hello,

The WWTP I want to model has already measured [i]Soluable COD[/i], [i]NH4[/i] and [i]NOx[/i] in the influent. I wonder how shall I include these input components in the influent fractionation blocks? What and how will be their connection to the other state- and output interface variables?

I have already tried different compositions but I get errors like duplicate parameter names, etc.

I appreciate if anyone could help me on this.

Regards,
/Salar

I can suggest the following:
[list]
[li]in the "General" page, add the components: "SCOD", "NH4" and "NOx"[/li]
[li]in the "Fractionation" page, open (load) the ASM(1) fractionation model: probably you need to delete the connection between the "TKN" and "NH" blocks and rather connect your measured (blue) "NH4" block directly to the "NH" (green) block (weight=1)[/li]
[li]you will also need to delete the connection between "COD" and "S_COD" (grey block = state variable); delete the "S_COD" block and replace it with your new measurement "SCOD"[/li]
[li]for "NOx", you need to do something similar[/li]
[/list]

Thanks a lot for your quick response. I suppose I now need to tell the program that X_COD = COD-SCOD and Organic N = TKN-NH4, right? Do I need to add connection with negative weights?

Sorry, but I need to understand the logic behind the connections?

Regards

Now I have made a new setup. I removed the state variables for Soluable and Particulate COD and connected the output interface variables directly to the measured data (as attached). Is it a problem that I do not have the State varibales for S_COD and X_COD in the fractionation?

https://www.dropbox.com/s/jeklmhdte7qlnr8/Fractionation.jpeg?dl=0

The layout looks totally fine to me.
It's obviously not essential to explicitly declare S_ and X_COD in the fractionation model: these are (algebraic) state variables, so as long as you don't need the information (e.g. for a plot) then it's ok.