if you are looking for the flow chart for a water treatment process you might look in the USC Sacraminto manual "Water Treatment I" (also known as the Ken Keri manuals)
if you are looking at building a model of a water treatment system you might look for some clear PVC pipe that would actually let you see the process in action.
you will want to be very carefull about using PVC in a RO system because of the high pressures that are required the PVC could break and cause harm.
I would also check with your local National Rural Water Assn. circut rider. for more help with this project.
When you say visualisation, you mean a computer system? If so, we have built complete water treatment plant with SCADA/PLC system. SCADA is an excellent system for visualisation and it is scalable and easily modified to visulaise your plant as it changes.