MultipleChoicePractice-2 Flashcards
Activated sludge tank microorganisms type
a. Does not affect the degree of treatment
b. Is not influenced by pH, temperature and sludge age
c. Is the same for all systems
d. Is influence by pH, temperature and sludge age
e. Is never controlled by adding chlorine to the RAS
D. Is influenced by pH, temperature and sludge age
The WAS rate affects
a. Chlorine demand
b. Amount of screenings
c. Primary clarifier effluent solids concentration
d. Bar screen
e. Effluent quality
E. Effluent quality
Microorganisms which are either molecular or combined oxygen are called a, Strictly anaerobic b. Strictly aerobic c. Do not exists d. Facultative e. Obligate aerobes
D. Facultative
Activated sludge basin foaming can be controlled by
a. Increasing DO
b. Increasing primary clarifier detention time
c. Bypassing the activated sludge basin
d. Increasing DO
E. Chlorinating the RAS
E. Chlorinating the RAS
Oxygen demand in an aeration tank could increase due to a. An increase in volatile solids b. Increase in BOD c. An increase in COD D. All are correct e. An increase in TOC
D. All are correct
Package plants usually
a. Are easier to operate than conventional plants
b. Do not require sludge wasting
c. Produce more sludge than conventional activated sludge plant
d. Operate as extended aeration plants
e. require an operator 24 hours a day
D. Operate an extended aeration plants
In order for a pond to be functioning correctly, ____ must be taking place
a. Rapid DO changes
b. Photosynthesis
c. Rapid BOD changes
d. Rapid temperature changes
e. Rapid pH changes
B. Photosynthesis
Daily facultative pond operational tests performed by the Operator are
a. BOD and SS
b. COD and BOD
c. MPN and ammonia
d. Nitrates and Nitrites
e. pH, temperature and DO
E. pH, temperature and DO
Ponds are normally located after
a. Trickling filter
b. Disinfection basin
c. Primary clarifier
d. None are correct
e. Secondary clarifier
D. None are correct
DO in a pond may be increased by
a. Mixing
b. Wind action
c. Diffused aeration
d. Controlling algae blooms
e. All are correct
E. All are correct
When using chlorine from a one ton cylinder which valve(s) does chlorine gas flow from
a. Top valve
b. Neither
c. Bottom valve
d. Makes no difference
e. Both valves
A, Top valve
Careful chlorination of the RAS will
a. Increase the pH
b. Inactivate filament organisms causing bulking
c. All are correct
d. Increase de-nitrification
e. Lower the BOD
B. Inactivate filament organisms causing bulking
Anaerobic digester methane gas normally contains at least how much methane
a. 75%
b. 65%
c. 25%
d. 45%
e. 35%
B. 65%
Aerobic sludge digester normal detention time is
a. About 30 days
b. One week
c. A few hours up to 1 day
d. About 1 year
e. About 7 days
A. About 30 days
Regarding anaerobic digester operations, which of the following statements is false?
a. pH changes are the first indicator that an activated sludge basis is going sour
b. Temperature only affects aerobic digestion not anaerobic digestion
c. Methane gas production will be approximately 35% of the gas produced from an anaerobic digester
d. The F:M ratio is the key to digester control
e. All are false
E. All are false
