Waste Water Treatment

water treatmentIn 2007, Paul Cavanagh, an engineer at Passaic Valley Sewerage Commissioners was having problems with an existing PLC program used to control both the mixed liquor channel level and to evenly split flows between twelve downstream secondary clarifier settling tanks.

Problem: existing control was slow and unstable


Solution: real-time VisSim model

To avoid these problems, a dynamic real-time simulation of the plant was developed with VisSim. The simulated plant was interfaced to a PLC, so the program could be tested before trying it on the actual plant. Simulations were run for extreme changes from normal dry weather to sudden high wet weather flows.

Experimenting was now possible without risk

Paul has given a paper on their success with VisSim: "PVSC Improves PLC Programming Using Real-Time Dynamic Simulation" at the ISA WWAC Symposium.