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)=........
Based on the treatment scheme, what type(s) of raw water is / are being treated? Groundwater
River water
Riverbank filtrate
Lake water
Infiltrated river water
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=..... 5 right answer
Total height (m)=........
QUESTION
Calculate the clean bed resistance of the rapid sand filter.
(m)
please post ans
Based on the treatment scheme, what type(s) of raw water is / are being treated? Groundwater
River water
Riverbank filtrate
Lake water
Infiltrated river water
please post answer
quite cheating on delft test
river bank filtrate and infliteradter river water
a) To determine the five quality parameters of the raw water that may not meet drinking water standards, we need to compare the given values with the standard limits.
From the given list, the following parameters do not meet drinking water standards:
1. Bacterial colony count: The standard limit is less than 100 cfu/mL, so if the count is higher than this, it does not meet the standard.
2. Ammonium: The standard limit is less than 0.2 mg/L, so if the concentration exceeds this value, it does not meet the standard.
3. Nitrite: The standard limit is less than 0.1 mg/L, so if the concentration is higher than this, it does not meet the standard.
4. Nitrate: The standard limit is less than 50 mg/L, so if the concentration exceeds this value, it does not meet the standard.
5. Iron: The standard limit is less than 200 µg/L, so if the concentration is higher than this, it does not meet the standard.
Therefore, the five quality parameters that may not meet drinking water standards are bacterial colony count, ammonium, nitrite, nitrate, and iron.
b) To identify the three water quality parameters changed during cascade aeration, we need to review the given list.
The three water quality parameters that are changed during cascade aeration are:
1. Oxygen: During aeration, oxygen is added to the water, increasing the oxygen content.
2. Carbon dioxide: Cascade aeration helps to remove excess carbon dioxide from the water, thereby reducing its concentration.
3. Total iron: Cascade aeration can cause oxidation of iron, leading to the formation of iron solids that can be removed through subsequent filtration steps.
Therefore, the three water quality parameters that change during cascade aeration are oxygen, carbon dioxide, and total iron.
c) The main purpose of rapid sand filters in this treatment scheme is to reduce two water quality parameters. To determine these parameters, we need to review the provided list.
The two water quality parameters that rapid sand filters aim to reduce are:
1. Turbidity: Rapid sand filters can effectively remove suspended particles and reduce the turbidity of the water.
2. Iron: Rapid sand filters are also capable of removing iron particles from the water, leading to a reduction in iron content.
Therefore, the two water quality parameters that rapid sand filters aim to reduce are turbidity and iron.
d) To calculate the total efficiency of oxygen addition, the number of cascade steps, and the total height of the cascade, we need to compare the oxygen concentration in the raw water with the minimum required concentration and the saturation concentration.
Given:
Minimum oxygen concentration = 7.6 mg/L
Oxygen concentration in raw water = 0 mg/L
Saturation concentration = 10 mg/L
Total efficiency of oxygen addition can be calculated as:
Total efficiency = (Oxygen concentration in raw water) / (Saturation concentration - Minimum oxygen concentration) * 100
Total efficiency = (0 mg/L) / (10 mg/L - 7.6 mg/L) * 100 = 0%
Since the raw water has an oxygen concentration of 0 mg/L, there is no oxygen present initially.
The number of cascade steps needed can be obtained by dividing the difference between the minimum and saturation concentrations by the assumed saturating concentration of each cascade step:
Number of steps = (Saturation concentration - Minimum oxygen concentration) / (Assumed saturation concentration per step)
Assuming each cascade step saturates the water with 2 mg/L of oxygen:
Number of steps = (10 mg/L - 7.6 mg/L) / 2 mg/L = 1.2 steps (rounded up to 2 steps)
The total height of the cascade can be calculated by multiplying the number of steps by the assumed height of each cascade step:
Total height = (Number of steps) * (Assumed height per step)
Assuming each cascade step has a height of 1 meter:
Total height = 2 steps * 1 meter = 2 meters
Therefore, the total efficiency of oxygen addition is 0%, the number of cascade steps is 2, and the total height of the cascade is 2 meters.