What is GPS-X?
Wastewater Process Libraries
Technical Specifications
Detailed Specifications


Basic Simulator Features

Steady state AND dynamic simulation software.
Completely interactive, allowing fast feedback and analysis of results, saves time compared to using "batch" (run and observe) simulators.
Built in unit conversion to non-SI units (e.g. US units).
Flexible data input and graphical output features (graphs, data files, DDE, etc.).
Communicates with spreadsheet programs (e.g. Microsoft Excel).
All forms are populated with default values from scientific literature.
Reads and uses real plant data as simulation inputs or for comparison to simulation results.
Automatic process consistency check and warnings.
Capable of supporting different languages.
Y2K compliant.

Advanced Simulator Features

Customizable (user can change models and interface forms, can add new models).
On-line automated real-time operation capability.
Can be connected to SCADA systems.
Automatic calibration, advanced sensor fault detection, process fault detection, automated forecasting available.
Contains built-in routines for On-Off, P, PI, PID, and lead-lag feedforward control simulation.
Built in PID controller tuning facility.
Dynamically links to Matlab for design and simulation of advanced model based control systems.

Unit Operations

Splitters, 2 to 5 streams
Combiners, 2 to 5 streams
Pumping Station (Wet Well)
Equalization Tank
Grit Chamber
Activated Sludge Tanks (CSTR, Plug-flow tank, Dual inlet plug-flow tank)
Sequencing Batch Reactor
Trickling Filter
Biological Aerated Filter
Rotating Biological Contactor
Deep Shaft
Primary Settlers (Circular and rectangular)
Final Clarifiers (Circular and rectangular)
Aerobic Digester
Anaerobic Digester
Sand Filter
Black Box (18 predefined transfer functions for empirical modeling, user customizable)
Tools (Signal tracking and alarm, pH model, sampler, flow or time based composite samples, PID controller, feedforward-feedback controllers, on-off controller, multivariable controller, low-pass filter)

Microsoft Excel interface to GPS-X
Customize an interface and run your GPS-X simulations from programs such as Microsoft Excel.

Wastewater Process Models

Biological Models

ASM1, ASM2, ASM2d, ASM3, Mantis (Temperature-dependent version of the ASM1), General (ASM1 extended to bio-P removal), VNP (Simplified bio-P model), Reduced (Simplified carbon-nitrogen model for control engineering applications), Filamentous Growth.

Settling Models

Double exponential, flux-based.

Influent Models

BOD-based (Input BOD, TSS, TKN and stoichiometry), ASM2 (Input COD, TSS, TKN and fractions of basic variables), States (input basic variables).

Fixed Film Models

ASM1, ASM2, Mantis (Temperature dependent version of the ASM1).

Anaerobic Model

Andrews-Barnett basic two-stage anaerobic model. VSS destruction, VFA generation, CH4 and CO2 generation, pH, ammonium toxicity.

Filtration Model

Iwasaki-Horner suspended solids capture model.


Empirical models for grit removal, dewatering, disinfection, filtration, and black box.


User Guide: Detailed description of interface features.
Technical Reference: Detailed description of all libraries and models.
Tutorial: 10 step-by-step lessons for beginners.
Getting Started: Easy installation notes for all supported platforms.
Entry Level Manual.
Advanced Control Module Manual.
All documentation is directly accessible from the software (in Adobe Acrobat PDF format).

System Requirements


90 MHz Intel Pentium PC
32 Mb RAM
175 Mb Hard Disk Space
SVGA (800x600, 256 colour) graphics card and 15 inch monitor
Windows 95, 98 or NT 4.0


350 MHz Pentium II PC
128 Mb RAM
1024 x 768 resolution, 64k colour, 17inch monitor