The Topic:

"Saving- recycling – reusing water at home or at school"

    The exercise given to the students to investigate and solve was about Sunstainable Development Goal 6 "Clean water and sanitation". Τhe purpose was to find defferent ways to save water

    For that reason, students designed a structure that will gather used water from the school sinks. It is transported through a tube containing natural filters and ethma. It then flows into a tank where its basic quality characteristics are studied. If the values of the measurments are suitable for irrigation with the help of a circulator, it is transferred to the irrigation network of the school garden. If the results are not satisfying, the water is returned to the school's sewerage system. There is also a sensor installed to control the overflow of water from the tank.

Summarizing, we have to examine and compare the quality of :

• tap water
• destile and
• the water from domestic use. 

Colorometric methods are used and we are measuring :

• Ammonium (NH₄⁺)
• Nitrate (NO₃^-)
• Nitrite (NO₂^-)
• Phosphate (PO₄^-3)
• pH
• Total Hardness

We we will use Arduino with: 

• Analog Conductivity Sensor /Meter (K=10) 10~100ms/cm
• pH sensor,
• Analog Turbidity Sensor
• Analog Dissolved Oxygen Sensor