100% VERIFIED ANSWERS|GRADED A+ | GUARANTEED PASS!!
What are the two important factors impacting the effectiveness of chlorination?
- answer-Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what?
- answer-Stabilization
Permanganate reactions are highly dependent on what factor?
- answer-pH
It is hardest to kill the organism that causes what illness?
- answer-Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and
at what concentration?
- answer-12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how
long?
- answer-15 to 45 minutes
Alum works best in a pH range of what?
- answer-5.8 to 7.5
What has little effect on colloidal particles because of their small size?
- answer-Gravity
What natural electrical force keeps colloidal particles apart in water treatment?
- answer-Zeta potential
, What does the zeta potential measure?
- answer-The number of excess electrons found on the surface of all particulate
matter
What device collects the settled water as it leaves the sedimentation basin?
- answer-The effluent launder
In solid-contact basins with fairly constant water quality parameters, how often
should the solids concentration be determined?
- answer-At least twice per day
What is the definition of decant?
- answer-To draw off the liquid from a vessel of any size without stirring up
bottom sedimentation
How often should sedimentation basins with mechanical sludge removal
equipment be drained and inspected?
- answer-Once a year
What is the most important reason to reduce turbidity?
- answer-To remove pathogens
What is the filtration flow rate through a manganese greensand pressure filter at 10
degrees C?
- answer-2 to 3 gpm/sq ft
When is a filter ripening?
- answer-When it becomes more efficient in particle removal
Virgin greensand can be regenerated by soaking the filter bed for several hours in a
chlorine solution of what?
- answer-100 mg/L
What precipitates can foul a cation exchange resin?
- answer-Iron and manganese
What process works best for sequestering manganese?
- answer-Polyphosphates and chlorine