River Xúquer water analysis I.E.S. “Hort de Feliu” – Alginet

1. Water cycle.

2. Historical precedents. The banks of the Xúquer are known for… Its developed and productive irrigation agriculture and its intensive use of fertilizers. Its infectious epidemics transmitted mainly by water. …but during the 20 th century… The consumption of fertilizers is shot up. Water health inspection is imposed.

3. Water analysis. Analytical tests selected: Color Smell Temperature Suspended matter Transparency pH Dry remainder Conductivity Alkalinity by Carbonates and Bicarbonates Water hardness due to calcium and magnesium ions. Nitrates Chemical Demand of Oxygen (CDO)

3. Water analysis. Real color, apparent color

3. Water analysis. Temperature

3. Water analysis. pH

3. Water analysis. Conductivity

3. Water analysis. Transparency

3. Water analysis. Water hardness

3. Water analysis. Nitrates

3. Water analysis. Alkalinity determination

3. Water analysis. CDO determination

4. River Xúquer itinerary. We have visited… Antella “assut” (small reservoir) Tous reservoir Sueca “assut” (small reservoir) …but due to lack of time, students could only collect water samples in Antella and Sueca… …both places represent parts of the river that can be analyzed to evaluate the river’s condition.

4. River Xúquer itinerary. Antella assut

4. River Xúquer itinerary. Antella assut

4. River Xúquer itinerary. Tous reservoir

4. River Xúquer itinerary. Tous reservoir

4. River Xúquer itinerary. Tous reservoir

4. River Xúquer itinerary. Sueca assut

4. River Xúquer itinerary. Sueca assut

4. River Xúquer itinerary. Estuary in Cullera

5. In the laboratory… We made the analysis we couldn’t make in the river… Color Suspended matters Dry remainder Hardness Nitrates Alkalinity CDO

6. Results (I). AntellaSueca Real colorTransparent Apparent color TransparentSlightly cloudy SmellNo smell Without smell or slightly earthy Organoleptic properties:

6. Results (II). AntellaSueca Temperature15.2 ºC19.5 ºC Suspended matters 45 mg/L53 mg/L Transparency–3,4 Dry remainder200 mg/L470 mg/L Physical properties:

6. Results (III). AntellaSueca pH88 Conductivity920 µS/cm1550 µS/cm Alkalinity due to carbonates 12 mg/L18 mg/L Total Alkalinity262.3 mg/L323.3 mg/L Chemical properties:

6. Results (IV). AntellaSueca Total hardness440 ppm600 ppm Nitrates< 10 mg/L CDO0.64 mg O 2 /L Chemical Properties:

7. Result interpretation. The temperature, pH and smell tests did not reveal any new information… …the absence of toilet or chemical smell shows that the water coming from river towns has been well depurated. During the trip…

7. Result interpretation. While conductivity increased significantly… …it shows an increase of dissolve salts. …two hypothesis are made: The calcareous rocks, which are very abundant within the river basin, bring a big quantity of carbonates of Ca and Mg. The fertilizers (nitrates) used excessively in agriculture and which are washed by irrigation water, end up in the river.

7. Result interpretation. The dry remainder shows an increase of the dissolved substances in the area between Antella and Sueca. The nitrate test let us know that there are minimum or even inexistent levels of fertilizers in the shape of nitrates. But the total hardness shows us a significant increase… …the ions Ca and Mg that reach the river make the water harder, a type of water that was already very hard by itself. Ready to check the hypothesis, the rest of analysis are carried out in the laboratory…

7. Result interpretation. The Alkalinity, on account of the carbonates and bicarbonates, doesn’t show any other newness for a river that flows on a bed which is on a calcareous land. While the CDO shows that the presence of organic matter is low… … little quantity of oxygen is required to oxidize it… …more oxygen remains for the aquatic fauna.

8. Conclusions. We have to think in a drastic reduction of fertilizers used in agriculture… We are at the end of the winter time and it’s a long time now that farmers threw these fertilizers onto the fields for the last time. Economically collapsed agriculture due to the low prices of the harvests. Farmers give up spending a lot of money in fertilizers.

8. Conclusions. The excessive hardness of the water is a natural quality of the river Xúquer… …the absence of pollution is justified by a higher control of the water which comes from the waste water of the cities. Now we have to educate the population so that they have more respect for the environment.

9. Other remarks. Someone is selling liquid rubbish that has no O 2 … …the farmers that use it can asphyxiate the roots of their crops, spread infectious illnesses and alter the fertility of their orchards.

9. Other remarks. In a wild nature park near the Tous reservoir, Iberian goats from “la Mola de Cortès” …

10. Thanks to… The people who have contributed to this project: English Department Geography and History Department Physics and Chemistry Department Biology and Geology Department Students of 3r ESO Students of 4t ESO Students of the option subject: Earth and Environment Science.