TURBIDITY & DETERGENTS
Measure biological parameters of the river Guadalquivir
Manuel González Gómez and Laura Gómez Briceño
Turbidity
Theoretical fundamentals
The turbidity is the expression of the optical property of the sample that causes that light rays are scattered and absorbed rather than be transmitted straight through the sample.
Materials
Test tubes
We need two for every stop
Test tube rack
Filter paper
Protocol
1) Take 2 portions of river water without filtering, 10 ml each one.
2) In tube 1 pour a portion, cover and leave to stand.
3) In tube 2 other filtered portion is poured and left to stand.
4) Compare, after 15 minutes, the tubes 1 and 2.
5) It is valued according to the following tableValue table
TURBIDITY DISAPPEARS ----------------------Value
Decanting ----------------------------------------------7
Filtration -----------------------------------------------3
NO DISAPPEARS --------------------------------------0
Results
Nº STOP-------------------VALUE
Stop 1 -----------------------3
Stop 2 -----------------------3
Stop 3 -----------------------7
Stop 4 -----------------------7
Stop 5 -----------------------7
Stop 6 -----------------------3
Stop 7 -----------------------0
Stop 8 -----------------------0
Stop 9 -----------------------0
Conclusion
Detergents
Theoretical fundamentals
Detergents produce foam and they add phosphate to the water (eutrophication).
Materials
Protocol
1) In a jar of glass or translucent plastic poured 40 ml of water without filtering and it covered.
2) Shake strongly, during 5 minutes.
3) If appears foam, which lasts more 3s, will be positive in detergents.
Value table
Negative in detergents ----------------6
Results
Nº STOP-------------------VALUE
Stop 1 -----------------------0
Stop 2 -----------------------0
Stop 3 -----------------------0
Stop 4 -----------------------0
Stop 5 -----------------------6
Stop 6 -----------------------6
Stop 7 -----------------------6
Stop 8 -----------------------6
Stop 9 -----------------------6