To remove suspended matter from muddy river water by filtration, sedimentation and chemical treatment.
Pour the muddy water in the beaker for some time to settle. Fold a filter paper in four stages as shown in the diagram. Place it in the glass funnel. You will see it does not stick to the funnel. One or two drops of water will make it stick. Now using a glass rod, pour the muddy water through the filter and see what happens. Collect the water that passes through in a beaker. This is called the filtrate. Pour the filtrate which, you will see, still contains tiny particles in suspension, into two tall jars. To one jar add some powdered potash alum, leave the other for comparison.
Notice the change when the muddy water is first allowed to settle ? What change do you notice after filtration as well as after potash alum is added ? Note if there any difference between the water in the two jars.
In this experiment you will have noticed the removal of suspended particles in water in three stages leaving a perfectly clear water. This is not necessarily pure, as bacteria, if present, cannot be seen with the naked eye, and they are so small that they cannot be removed by filtration.