t hether each of the following statements are true or false: T F Stoke\'s Law can be used to model the oxygen sag curve T F Phosphorus is more often a limiting nutrient than nitrogen T F Hardness is more often a problem in surface water than in groundwater T F BODs measures CBOD, not NBOD T F The amount of available substrate will affect the biomass growth rate cons 2. [4 points] Lis t two advantages and two disadvantages of chlorination as a disinfection method. 3. [4 points] Explain the main advantage and disadvantage of combined sewer systems. secondary clarification in wastewater treatment. Consider removal mechanism(s) and the main constituent(s) to be removed. 4. [4 points) List one similarity and one difference between primary sedimentation and Solution 2. Advantages of Chlorination - Residual chlorine helps in disinfection against further contamination throughout the flow of water through pipes and at the time of usage. -relatively cheap ,simple,reiable and quick Disadvantages of Chlorination -imparts a peculiar taste to the water -toxic to aquatic life -chlorine is corosive 3. Advantages -stormwater and wastewater are managed together -use of runoff for wastewater transportation is helpful in water conservation -moderate costs -health risk and insect problems are reduced by dilution of wastewater Disadvantages -Installation cost is high because of larger size sewers. -Not suitable for areas of unpredictably varying storms. -Larger sized and more efficient pump and pipe systems needed. -Expertise is required for design. 4. Similarity- Sedimentation by gravity is used for settling of matter within a given settling time. Difference: Primary clarifier mainly removes suspended impurities and in secondary clarifier microbes are removed by settlement..

1. t hether each of the following statements are true or false: T F Stoke's Law can be used to
model the oxygen sag curve T F Phosphorus is more often a limiting nutrient than nitrogen T F
Hardness is more often a problem in surface water than in groundwater T F BODs measures
CBOD, not NBOD T F The amount of available substrate will affect the biomass growth rate
cons 2. [4 points] Lis t two advantages and two disadvantages of chlorination as a disinfection
method. 3. [4 points] Explain the main advantage and disadvantage of combined sewer systems.
secondary clarification in wastewater treatment. Consider removal mechanism(s) and the main
constituent(s) to be removed. 4. [4 points) List one similarity and one difference between
primary sedimentation and
Solution
2.
Advantages of Chlorination
- Residual chlorine helps in disinfection against further contamination throughout the flow of
water through pipes and at the time of usage.
-relatively cheap ,simple,reiable and quick
Disadvantages of Chlorination
-imparts a peculiar taste to the water
-toxic to aquatic life
-chlorine is corosive
3.
Advantages
-stormwater and wastewater are managed together
-use of runoff for wastewater transportation is helpful in water conservation
-moderate costs
-health risk and insect problems are reduced by dilution of wastewater
Disadvantages
-Installation cost is high because of larger size sewers.
-Not suitable for areas of unpredictably varying storms.
-Larger sized and more efficient pump and pipe systems needed.
-Expertise is required for design.
4. Similarity- Sedimentation by gravity is used for settling of matter within a given settling time.
Difference: Primary clarifier mainly removes suspended impurities and in secondary clarifier
microbes are removed by settlement.