Research Focus Laboratory - NTU MSE
PPT - Turbidity and Chlorophyll PowerPoint …
Then, it is photosynthesis light quantum flux density to show the number in which the light quantum at 700nm wavelength from 400nm which is the chlorophylloid absorption wave length area was emitted at unit time and per unit area.
Nephelometric Turbidity Units (NTU) ..
Turbidity is a measure of the amount of light that passes through a waterbody and the amount of suspended sediments in the water. Suspended sediments in the water may include silt and clay, organic and inorganic matter, and living or dead microscopic organisms. Generally, a reading of 25 NTU indicates water with good clarity. NTU means nephelometric turbidity units. A reading 25 NTU may cause problems in the ecosystem. A useful working rule is that seasonal mean turbidity should not change by more than 10%. We developed an appropriate monitoring program as we know that suspended sediment concentrations change over time. As you can see by our turbidity results in our wetlands, our results are between five and sixty NTUs. Most results are within the 25 NTU range which is quite normal as stated above. Though in the months of March, November, January and February the turbidity of the ponds peaked above 25 NTUs. During these periods the water level had dropped due to evaporation and the water was more concentrated. Any disturbance of sediments quickly made the shallow waters appear muddy although readings were taken in undisturbed areas. Summer rain may have caused suspended sediments to increase because of soil and bank erosion or re-suspension of stored sediment in the wetlands. Runoff after heavy summer showers from the schools drain empties into Koopoolang Pond The effect of this high concentration of suspended sediments can cause severe effects on the wetlands. As light penetrating through the water is reduced, the photosynthesis of aquatic plants will be restricted, maybe even leading to the death of some species and lowering the dissolved oxygen content in the water. This does not appear to be a problem in our wetland.