True and False - 4 Flashcards
(25 cards)
Sludge bulking is caused by light sludge not settling properly
T
A rise in temperature should be expected when air is compressed
T
When an activated sludge plant is first started, you should expect to see aeration basin foaming
T
A WAS or RAS flow rate change of 25% in one day will have little effect on the plant
F
pH has little effect on the activated sludge plant
F
Filamentous microorganisms can be reduced by increasing aeration basin dissolved oxygen concentration
F
The return sludge rate and wasting rate are the same for pure oxygen and conventional activates sludge plants
F
Facultative bacteria can use oxygen from sodium nitrate
T
A longer MCRT is required for nitrification than conventional activated sludge treatment
T
If solids settle to the jar bottom within an hour and then rise before two hours, the activated sludge plant is upset
T
Do meters normally cannot be used to measure Do concentration accurately below 1 mg/L in the field
T
Three feet in the maximum depth for wastewater treatment ponds
F
Algae growth in a wastewater pond lowers DO and increases pH
F
Chlorine can be withdrawn at any rate from a chlorine cylinder
F
Chlorine withdrawal rates are lower than sulfur dioxide withdrawal rates for the same size cylinder
F
Sodium hypochlorite use is considered less hazardous than chlorine gas however, its cost makes sodium hypochlorite unattractive
F
You have added enough chlorine to wastewater if you have met the chlorine demand
F
Be sure to properly label a leaking chlorine cylinder before shipping it
F
Chlorine gas cylinders should be isolated before taking the chlorinator off line
T
Dechlorination is often accomplished with sulfur compounds
T
The pH test is preferred for anaerobic digester control over the acid/alkalinity relationship
F
Anaerobic digesters may become stuck if the pH drops below 6.7 or increases above 7.5
T
The volatile acid to alkalinity ratio is normally around 0.1 when the digester is not stuck
T
When an anaerobic digester is going sour, the pH will drop before the volatile acid/alkalinity ratio
F
