Just doing a bit of research, can anyone suggest which of Autodesks software is best suited to modelling treatment processes and lift stations etc.
I just finished a WWTP project. The piping was done with alignments and profiles (the pressure pipe tools came out too late to use them) while the detailing was done with plain Autocad and a $300 pipe symbol utility.
There is Bentley's Autoplant (they have an Autocad version) which is designed for industrial piping systems but you'll have to invest quite a bit of resources to purchase and implement it. Also look at the Autodesk Plant products pages.
I don't do animations, sorry.
The plant component drawings were 2D also so it would require considerable work to produce a 3D model which was not in the budget.
Bill is right to note the ADESK plant software I referred to is more for drafting. I don't know of any products that are designed for modeling the performance of a treatment plant.