Hi Hoa,
I guess that the discharge you mention in your correlation formulation is the liquid discharge.
Be aware that the QBOR array in conlit subroutine refers to the solid discharge, not the liquid one!
If you try to use the QBOR array from Telemac2D declarations (liquid discharge), I think there will be a conflict between the 2 arrays because they have the same name...
I suppose that the liquid discharge is also prescribed (and so known), so in your case, I would use a liquid boundary file containing the time series of the concentrations previously computed from the liquid discharge.
I hope it helps.
Regards,
Laurent