What is the difference between algae and cyanobacteria
Algae are dispersed within water, cyanobacteria is on top of water.
Is algae stronger than cyanobacteria?
No, cyanobacteria is stronger because it is on top (adaptation), if N2 is limited in water, it can uptake from the atmosphere.
How do you classify insoluble substances
Non-settling, settling, suspended
What are electrolytes
Dissolved ions (Ca, Mg, Na…)
What are non-electrolytes?
Dissolved non-ionic (O2, CO2,…)
In what forms does nitrogen occur in water?
Nitrites,Nitrates, Ammonia
What is the organic origin of ammonia
decomposition of animal and plant organic nitrogen, sewage and runoff from agriculture.
What is the inorganic origin of ammonia
Nitrogen fertiliser, contamination of surface and groundwater, wastewater from thermal processing of coal
What happens to water when ammonia/ammonium ion is introduced?
increase pH
what is the equilibrium at 20C when ph is bigger than 9.3?
equilibrium is to the left, toxic form of NH3
what is the equilibrium at 20C when ph is smaller than 9.3?
equilibrium is to the right, non toxic form of NH4 ion
NH4, NH3 what is more toxic
NH3 is more toxic
What happens when temperature/pH increases
percentage of dissoved total ammonia increases
What is the volatile form of ammonia
unionised
What is the non-volatile form of ammonia
ionised
Why is the ammonia toxic to aquatic life mainly?
Because of the unionised form of NH3
What are the sources of Nitrite (NO2)
Atmospheric water, industrial waste
Why is nitrite a good indicator of pollution in groundwater?
It is unstable in water, and in groundwater there are low oxygen concentrations
What is the effect of nitrite on fish?
toxicity
What are the sources of nitrate (NO3)
Atmospheric water, Fertilisers
When is the largest concentration of nitrates?
in the winter
How do you reduce nitrate?
nitrites, elementary nitrogen
Source of cyanide?
There is no natural source, industrial waste water