a) Which five quality parameters of the raw water may not meet drinking water standards?

Bacterial colony count (less than 100 cfu/ml)
Ammonium (less than 0.2 mg/l)
Nitrite (less than 0.1 mg/l)
Nitrate (less than 50 mg/l)
Iron (less than 200 µg/l)
Turbidity (less than 4 FTE)
Oxygen (greater than 2 mg/l)
Temperature (less than 25 °C)
Hardness (between 1 and 2.5 mmol/l) Pesticides (less than 0.5 µg/l when summed up)

b)Which three water quality parameters are changed during cascade aeration?

Ammonium
Nitrite
Nitrate
Chloride
Total iron
Oxygen
Carbon dioxide
Temperature
Hardness
pH
Pesticides

c)The main purpose of rapid sand filters in this treatment scheme is to reduce two water quality parameters. Which ones?

Ammonium
Nitrite
Nitrate
Chloride
Iron
Turbidity
Oxygen
Temperature
Hardness
pH
Pesticides

d) Minimum oxygen concentration should be 7.6 mg/l, concentration in raw water is 0 mg/l and you can assume a saturation concentration of 10 mg/l. Calculate the total efficiency of oxygen addition, the number of cascade steps and the total height of the cascade.

Total efficiency=......
Number of steps=.....
Total height (m)=........

A)??????????????

B)??????????
C)ammonia and iron
D) 1)???????????????
2)5
3)2meters