A Comprehensive Review on Performance Evaluation and Modelling of Wastewater Treatment Plants Using GPS-X

Every day, cities and industries pour vast quantities of used water into the environment. Before this water can safely return to rivers or lakes, it must pass through treatment plants that strip away harmful substances. These facilities rely on complex biological and chemical processes to clean the water, but keeping them running efficiently is a constant challenge. Operators must balance how well the water is cleaned against how much energy it takes to run the machinery and how much it costs to operate. If the process is too aggressive, it wastes electricity; if it is too gentle, the water remains polluted. To solve this puzzle, engineers use sophisticated computer programs that act as virtual laboratories. These tools allow them to test changes on a screen before making any physical adjustments to the real plant, helping to predict how the system will react to different conditions.

One such program, known as GPS-X, has become a standard tool for simulating these wastewater treatment processes. A recent comprehensive review by researchers Mohammad Aljamhawi and colleagues examined how effectively this software is used across the globe. The team analyzed dozens of studies published between 2002 and 2025 to understand how well the computer models match reality. They looked at how the software handles the removal of common pollutants, how much energy different treatment setups consume, and whether the cost of running these plants can be reduced through better planning. Their goal was to determine if these digital simulations are reliable enough to guide the design and operation of the massive infrastructure that keeps our waterways clean.

The researchers found that the software is highly effective at predicting how well a plant removes traditional pollutants. In the studies they reviewed, the computer models successfully simulated the removal of total suspended solids, which are tiny particles floating in the water, with an efficiency reaching up to 94.2 percent. It also performed well in tracking the breakdown of organic waste and the removal of nutrients like nitrogen and phosphorus, which can cause algae blooms in natural water bodies. However, the software faces a steeper challenge when dealing with newer types of contaminants. When researchers tried to simulate the removal of microplastics and pharmaceuticals, the predicted efficiency dropped significantly, ranging from roughly 66 percent for microplastics to 72 percent for medicines. This suggests that while the digital tool is excellent for standard operations, it still needs refinement to accurately predict how plants handle these emerging threats.

Energy consumption emerged as another critical factor in the review. Wastewater treatment plants are energy-intensive, largely because they must pump air into tanks to help bacteria break down waste. The studies analyzed showed that energy use varied widely depending on the complexity of the treatment process. The most efficient setups consumed about 3.1 kilowatt-hours of electricity for every cubic meter of water treated, while more complex systems required up to 5.2 kilowatt-hours. The software proved useful in identifying these differences, allowing engineers to test scenarios that could lower energy use without sacrificing water quality. Similarly, the cost of operation was found to fluctuate between 10 and 18 cents per cubic meter, with the price largely driven by the energy required and the number of steps needed to clean the water.

Despite these successes, the review highlighted that a computer simulation is never a perfect copy of the real world. The accuracy of the GPS-X models depends heavily on how well they are calibrated, a process where engineers adjust the software's settings to match data collected from an actual plant. When this calibration is done carefully, the software can predict plant performance with high precision, showing a strong correlation between the simulated results and what actually happens on the ground. However, if the input data is incomplete or the plant conditions change rapidly, the model can drift away from reality. The researchers noted that the software currently lacks the ability to automatically incorporate real-time data as it flows in, which limits its ability to adapt instantly to changing conditions.

The authors concluded that while GPS-X is an indispensable tool for optimizing wastewater treatment, it is not a standalone solution. It works best when combined with careful data collection and ongoing adjustments. The review suggests that the future of this technology lies in integrating it with real-time monitoring systems and advanced analytical methods to make the simulations more dynamic and responsive. For now, the software remains a powerful way to test ideas and improve efficiency, helping engineers design plants that are cleaner, cheaper, and more sustainable, even as the challenges of water pollution continue to evolve.