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Pedagogic content

  • Mobility of pollution in water media
  • Artificιal “pollution”
  • Advection and diffusion of water pollutants into the ground water.


Knowledge of: hydrological cycle, ground water definition, wastewater, pollutants

New competencies targeted


  • Identify the different water pollution sources and trying to understand the impact to humans.
  • Learn important concepts related to advection and diffusion processes of pollutants in the water media
  • Understand how water gets from the ground after its rained to the rivers and oceans.



(In the science laboratory / classroom or field).
Students are working in pairs or small groups of 4 and they follow the instructions below :


Lay down a few paper towels and put the egg carton on top.


Begin pouring water into one of the cups at one end of the egg carton and watch as the water flows from cup to cup. Stop pouring once each egg cup is full.
The mobility of water in the egg cases needs a slight inclination, be sure that you have provided this circumstance.


Pour about 1 small spoon of flax meal (flax seeds) into one of the end cups. Watch as the water carries it from cup to cup.


Starting in a cup at the opposite end of the egg carton, add about 10 drops of coloring (such as egg coloring). Give the cup with the coloring a slight stir and watch as it slowly flows into the cups around it.


Leave your experiment out for an hour and notice water mobility and coloring seeping out of the bottom of the egg carton and saturating the paper towels under the carton.


The students should repeat the whole procedure with different “pollution” initial sources (e.g. filter coffee) and food coloring.


Students discuss with their educator about what each material represents in the aquatic environment and come to conclusions about waters behavior.


Educator asks the students to describe an example of water pollution that they know in their city/region/country


Students are interviewing an expert (environmental scientist) about water pollution issues in their regions.


Students present the results of their experiment and also the remarks of the interview as a poster in the rest of the school community

Additional Info

Type of Activity: Exhibition
Target Audience: From 13 years old
Place: Field campaign, Science laboratory
Material need: tray or table
paper towels
empty egg carton
flax seeds, filter coffee, or another powder, egg coloring material or food coloring
Duration of Activity: PREPARATION:

2-3 hours

Authorship and ressources conditions to use: HCMR (Educational Unit)No registration or authorization for use is required
Note by Author:

This activity should take place in the laboratory or in an aquatic system such as pond, lake, streams or at the coastal zone.

Interpretation: The students should understand that the neigboring cups represent the water media of the pollution event such as rives, lakes, streams, ponds oceans etc. The paper towels represent the aquifer (the underground water source-groundwater).

In this experiment, the egg carton represents how water media (such as streams, ponds, lakes, rivers, and oceans), are connected to each another. The advection and in general the mobility of pollutants are observed after adding artifically “pollution” substances and colored powders into the first cup.

The “pollutants” areadvected from the initial place (where the substance isadded), to the neighboring water media (whichcould be far away from where the initial pollution event started). After leaving the egg carton for awhile, the water and pollution (such as the egg coloring material) started to seep out through the bottom and onto the paper towels.

This is an example of how pollution that goes into a body of water can advected further into the ground and pollute areas around a stream or lake or ponds or aquifers. In the last case, when groundwater becomes polluted, it can harm plants and subsequently the humans.

This activity is an introduction for observing the mobility of pollution in water media.

This experiment represents how media of water (such as streams, lakes, rivers, and oceans), are connected to each another. The advection and diffusion of such pollutants are observed by controlling the movement of artificιal “pollution” from the initial cup to the neighboring cups. Similar phenomena can be observed for the advection and diffusion of water pollutants into the groundwater.

Topic of this Experiences: Sea Water Quality
Additional resources: Pdf Version