B Wastewater 2017 Study Guide Flashcards
When nitrification increases in an activated sludge system, what other changes would be expected?
F/M MCRT MLSS
Decr. Incr. Incr.
By increasing the sludge feeding rate to your anaerobic digester, you decrease the detention time and?
Increase the rate at which alkalinity is depleted
What is gasification of a gravity thickener primarily caused by?
Anaerobic sludge
Before using the tubing in a lab, the ends of the glass should be?
Flame Polished
Evapotranspiration is?
Water removed from an area by plants and evaporation
In anaerobic digestion, what does a pH decrease indicate?
Methane producers are reacting too slowly
A plant treating 5.0 MGD of domestic wastewater has primary settling, aeration tanks, final settling, aerobic digestion and chlorine contact chambers. Which groups of tests are most important to assure proper operation and compliance with existing rules?
CBOD, CL2, D.O., pH, settle- able solids, TSS and volatile solids
When operating an Advanced Treatment facility using chemical treatment for solids removal, you discover high flows entering the system. You should?
Prepare to feed a greater quantity of chemicals
When using polymer in a gravity thickening process for sludge, when would more polymer dosages be required? When the:
Hydraulic loading rate increase
Head loss in a gravity filter is determined by?
Measuring the water pressure above and below the filter media
What dosage of chlorine can be fatal in just a few breaths?
1000 ppm
Which statement best describes at which speed a belt filter press should be operated?
The ideal belt speed is the slowest the operator can maintain without washing out the belt
What steps should the operator take if “washing out” occurs while operating a belt filter press?
Lower flow rate and increase belt speed
FDEP approved continuous on-line analyzing of reclaimed water effluent includes analyzing for?
pH, chlorine residual and turbidity
Lime is used more frequently for phosphorous removal than Aluminum Sulfate because Aluminum Sulfate:
Is more expensive than lime
Preventive maintenance of electrical motors includes?
Keeping the motor clean of dust, dirt and moisture
According to Chapter 62-600,FAC,Domestic w/w facilities, the basic disinfection requirement ( using chlorine) is a:
0.5 mg/L minimum total chlorine after 15 minutes contact time at peak hourly flow
What causes a loss of vacuum in a vacuum filter?
Filter media misalignment or tear
A chlorinator with automatic, proportional-to-flow controls will not feed enough chlorine to produce the proper residual. Sampling shows that at some hours of the day there is an adequate residual. However at other times there is not. Which of the following would correct the chlorine problem?
Repair the automatic control features of the chlorinator
The plant EFF Coliform count has failed to meet the required standards for disinfection. The supply of disinfectant is not the problem. There is adequate chlorine residual. To confirm the cause, it is most relevant to check the?
Chlorine Contact Chamber for short circuiting
How is the Fecal Coliform parameter evaluated?
The concentration is estimated by using the most probable number (MPN) method or the membrane filter (MF) method
When reading the level of a column of liquid in a graduated cylinder, burette or manometer, you should?
Record the level of the bottom of the meniscus of the liquid being measured
The plant EFF Coliform count has failed to meet the required standards for disinfection. The supply of disinfectant is not the problem. There is adequate chlorine residual. The best solution is to?
Install additional baffling
If a sand drying bed has a problem with the media becoming clogged, what should the operator do first?
Rake the surface of the bed, removing the upper 2 to 3 inches of sand, and replace the sand with fresh sand
What would be the usual approach to measure the impact of a discharge to receiving waters?
Take a measurement in the upstream, unaffected, area and compare to a down stream affected area
Which does not represent a potential hazard of working in a wastewater treatment laboratory?
Hypothermia
An instrument used in a laboratory that measures the intensity of color or particular wavelength is a?
Spectrophotometer
A gravity filter experiences rapid build-up of head loss. What could be a probable cause?
Incomplete backwash cycle
What problems may develop during the injection of reclaimed wastewater into deep wells?
Contamination of groundwater
According to state regulations, a wastewater plant shall maintain a pH in the effluent after disinfection within what range?
6.0-8.5
In Chapter 62-699, FAC, Treatment Plant Classification and Staffing, wastewater treatment plants are classified in order to prescribe the lowest class of certified operators who will be permitted to operate the treatment plant. This classification system is based on what (2) two factors?
Design flow and treatment type
The recovery of a stuck anaerobic digester can be accelerated by neutralizing the acids with a caustic material like?
Lime
When operating an advanced treatment facility using chemical treatment for solids removal, you discover high flows entering the system. The first step you should take is to?
Prepare jar tests to determine dosage that will be good for decreased detention time
Even though a process control test is accurately performed, which one of the following could result in meaningless findings?
The sample not being representative of the process stream being sampled
It takes about 22% less O2 to process 1 lb. of carbonaceous waste than 1lb. of nitrogenous waste. What does this indicate?
Additional D.O. is required to nitrify
To determine the location and amount of lowest dissolved oxygen downstream from a wastewater effluent discharge, it is necessary to?
Conduct an oxygen profile of the stream
A sand and gravel filter had been working well, but eventually head loss occurred. Performance did not improve significantly following backwashing. What is the most probable cause?
The backwash time was too short
The floating cover on a primary anaerobic digester appears to be tilting. Inspection of the rollers indicates that they are not the problem. Probing the annular space results in finding a thick scum accumulation. What should be done at this point?
Use chemicals or degreasing agents, then hose down the scum blanket through the inspection ports
Nitrification in the activated sludge process?
Decreases alkalinity and pH
Which statement is most correct concerning dissolved oxygen content in water?
An increase in temperature causes a decrease in dissolved oxygen concentration
Rapid accumulation on the surface of a single media sand filter results in very rapid head loss. The solution is?
Improve prior clarification
In the microscopic exam of the mixed liquor, you observe a dominance of rotifers and nematodes. What would this be indicative of?
Old sludge that settles rapidly, leaving pin floc