Water Purification Stages
Run dirty water through screening, coagulation, sedimentation, filtration and disinfection.
What the Water Purification Stages shows
Run dirty water through screening, coagulation, sedimentation, filtration and disinfection. Free, no signup, runs in your browser. Built for real-world chemistry, the water purification stages runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Switch treatment stages on or off and run dirty water through each one.
How to use the Water Purification Stages
In the Water Purification Stages, use the controls to change Switch stages on or off. The simulation reacts instantly.
In the Water Purification Stages, press "Run the water through", "Reset" to start, reset or change what is happening.
Start with this experiment: Switch off coagulation. Drag any glowing handle, object or slider with your mouse or finger and the Water Purification Stages responds in real time.
Change one setting at a time and watch which readout moves, then compare it with this idea: Each stage removes a different kind of contaminant.
Things to try
Switch off coagulation.
Switch off disinfection.
Run all stages.
Find the weakest stage.
The science behind it
Each stage removes a different kind of contaminant.
Coagulants make tiny particles clump so they settle out.
Disinfection with chlorine or UV kills the bacteria that filters miss.
A worked example with real numbers
CT = 1.5 × 20 = 30 mg·min/L Log removal = −log₁₀(0.001) = 3 log Order: screening, coagulation, sedimentation, filtration, disinfection.
Tips and common mistakes
Tips
- Turn off a stage and see which contaminant remains.
- Run the full chain to see each stage clean the water.
- Reset to compare.
Common mistakes
- Clear water is not always safe water; microbes are invisible.
- Filtration alone does not kill bacteria.
- Skipping coagulation overloads the filters.
Where this is used
Water treatment plants protect public health around the world by combining these stages.
Who is this simulation for?
Students, teachers and citizens interested in environmental science, climate and water, who want to see the chemistry behind the headlines. A good first experiment in the Water Purification Stages: Switch off coagulation. The key relation to keep an eye on: Disinfection dose CT = concentration × contact time; log removal = −log₁₀(N / N₀).
For teachers: project the Water Purification Stages on the board, let students predict the result, then run it together and test this: Switch off disinfection. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why is coagulation needed before filtering?
Very tiny particles pass through filters. Coagulants make them stick together into larger clumps that settle or get caught.
Why add chlorine at the end?
To kill remaining bacteria and viruses and keep the water safe as it travels through pipes.
Is the Water Purification Stages free to use?
Yes. The Water Purification Stages is free, needs no signup or download and runs in your web browser. It is part of the Real-World Chemistry group of AZRS simulations.
Does the Water Purification Stages work on a phone or tablet?
Yes. The Water Purification Stages takes touch input as well as mouse input, so you can use its 1 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
