Water Treatment Operator Level 1 real
Questions and answers 2024/2025
latest/updated exam
What are the two important factors impacting the effectiveness of chlorination?
Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what?
Stabilization
Permanganate reactions are highly dependent on what factor?
pH
It is hardest to kill the organism that causes what illness?
Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration?
12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long?
15 to 45 minutes
Alum works best in a pH range of what?
5.8 to 7.5
What has little effect on colloidal particles because of their small size?
Gravity
What natural electrical force keeps colloidal particles apart in water treatment?
Zeta potential
What does the zeta potential measure?
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?
The effluent launder
In solid-contact basins with fairly constant water quality parameters, how often should the solids
concentration be determined?
At least twice per day
What is the definition of decant?
To draw off the liquid from a vessel of any size without stirring up bottom sedimentation
Questions and answers 2024/2025
latest/updated exam
What are the two important factors impacting the effectiveness of chlorination?
Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what?
Stabilization
Permanganate reactions are highly dependent on what factor?
pH
It is hardest to kill the organism that causes what illness?
Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration?
12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long?
15 to 45 minutes
Alum works best in a pH range of what?
5.8 to 7.5
What has little effect on colloidal particles because of their small size?
Gravity
What natural electrical force keeps colloidal particles apart in water treatment?
Zeta potential
What does the zeta potential measure?
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?
The effluent launder
In solid-contact basins with fairly constant water quality parameters, how often should the solids
concentration be determined?
At least twice per day
What is the definition of decant?
To draw off the liquid from a vessel of any size without stirring up bottom sedimentation
