Class 1 Wastewater Test
One electrical horsepower is equal to?
0.746 kilowatts
What is the typical range for mixed liquor concentration in an activated sludge plant?
1,000 to 5,000 mg/l
What is the typical range for influential BOD5?
100-259mg/l
One horsepower is equal to lifting?
33,000 pounds one foot in one minute
Sludge retention time (SRT) in a conventional activated sludge system should be?
5-15 days
Raw wastewater typically has a pH near?
7
What percent organic matter would you expect domestic wastewater to be?
75%
Municipal wastewater consists of approximately what percentage of water?
99.9%
Too high a discharge head will cause a pump to pump?
A reduced volume
Complete mix, step aeration, and contact stabilization are modifications of what process?
Activated sludge
A centrifugal pump is not discharging properly, what could be the problem?
Air leaks, speed to low, and/or damaged impeller
Which is not the objective of a pretreatment program?
Allowing industrial waste to be hauled from the treatment site
Nitrification is the conversion of?
Ammonia to nitrate
The lower level in a facultative lagoon is?
Anaerobic
A test that provides the relative measure of the amount of food available to the biological system, the degree of stabilization of the wastewater, and the effect of the effluent on the receiving stream is called?
Biochemical oxygen demand
The type of pump that is most common in a wastewater treatment facility is a?
Centrifugal
Sewers that convey both sanitary wastes and storm waters are called?
Combined sewers
In the formula Q=V(A), Q is defined as rate of flow expressed as?
Cu. Ft. / sec.
The component in the aeration system that breaks up the air bubbles is known as the?
Diffuser
Th purpose of the biological process of trickling filters, RBCs and combined processes is to remove?
Dissolved Organics and finely divided organic solids
Which is not a form of horsepower applied or used by a pump?
Electric horsepower
When cells use their own protoplasm and start to eat each other, as food to provide the energy to maintain life, this is known as what type of growth?
Endogenous
Why is sampling of wastewater important?
Evaluate the wastewater treatment process
Low solids in the return sludge could be an indication of?
Excessive wasting
Head is a measure of pressure always expressed in?
Feet
Grab samples taken in sizes that correspond to the flow rate are known as?
Flow proportional
Anaerobic decomposition of wastewater produces?
Hydrogen sulfide
Disinfection of WWTP effluent ???? Or ????? Pathogenic bacteria, viruses, and amoebic cysts commonly found in wastewater.
Inactivates or destroys
As the temperature ????? Microorganisms accelerate consumption of Organics
Increases
On a pump curve, as the head ?????, output ?????
Increases, decreases
MSDS stands for?
Material Safety Data Sheet
What is the purpose of the Biochemical Oxygen Demand Test?
Measures the amount of oxygen used by microorganisms
Two of the most commonly used methods of supplying air to the wastewater treatment process are?
Mechanical and diffused aeration
A mixture of activated sludge and wastewater is called?
Mixed liquor
The mixture of wastewater and returned activated sludge in the aeration tank of an activated sludge system is called?
Mixed liquor
An operator monitors the treatment process for parameters found in the?
NPDES permit
What does NPDES stand for?
National Pollutant Discharge Elimination System
Three controls for activated sludge operation are?
Number of microorganisms, D.O. And treatment time
The centrifugal pump has how many moving parts?
One
Disease causing organisms are called?
Pathogens
What conditions are necessary for a natural treatment system to be a good choice?
Plentiful and good soil condition
Pumps that discharge a definite quantity during each plunger movement are know as?
Positive displacement pumps
What is the primary objective of the Clean Water Act of 1972?
Restore and maintain the chemical, physical, and biological integrity of water in the US
The 30-minute settling data, when combined with the mixed liquor suspended solids data, can be used to calculate the parameter called?
Sludge volume index test
The total energy required to lift wastewater from one level to another is called?
Total dynamic head
Which test measures the solids in and out of the treatment process for plant efficiency?
Total suspended solids test
Ultraviolet light disinfection will not be effective when?
Turbidity is too high
All activated sludge processes must gave a system to remove excess microorganisms. What is the name of this system?
Waste activated sludge
MCRT is used to indicate when activated sludge should be?
Wasted
Liquid waste collected from residential, commercial, and industrial areas and conveyed to a central location is generally called?
Wastewater
